.300 Blackout; Anyone tried CFE BLK?

[Rich@CCC]

I finally finished my .300 pistol so I loaded some trial .300blk rounds yesterday. I went with CFE BLK powder based on a local shop's loading SME recommendation.

This load is a shot in the dark guesstimate as there was no published data for the bullets that I could find.

modified LC 5.56 brass
CCI small rifle primer
Lapua 185gn Spitzer
13.4gn CFE BLK
OAL 2.2"

The powder charge is about 80% of the minimum charge listed by Hodgdon for a 180 GR. SPR SP. The Lapua pills are pulled bullets I picked up years ago at a gun show. My .308 didn't like them so they've been sitting on the shelf with no purpose till now.

I will be casting 230gn bullets with a Lee mold for subsonic loads ASAP
http://www.titanreloading.com/molds/bullet-molds/30-cal/lee-dc-mold-tl309-230-5r

So has anyone used this powder?

14691

14692

[Rich@CCC]

So, I finally got to the range to test this load. The cheap, chi com flip ups are bore sighted at 30' and this group was fired off hand, no sling from 35yds. The group was better than I expected but nothing to write home about. I was primarily interested in whether the load would cycle the action reliably.

14758

The problem I ran into was odd. None of the seven test rounds would go into battery from bolt lock. I finally gave the forward assist a tap(I know, shut up. I know!) and pulled the trigger. Bang! The case ejected and the next round fed but did not lock into battery. I tapped the FA again and Bang! same story. Every round fired and ejected. Every round fed but would not go into battery without assistance. The last round locked the bolt open on ejection. All of these cartridges measured well within spec.

When I got back to the shop, I measured the fired cases and they were still within spec. Actually they were under spec in all aspects. I tried to chamber an expended case and it did the same thing. I had to tap the FA to get the bolt to lock in battery. Then I had to mortar the stick to eject the empty case.

I then loaded the same seven cases again. Same exact set up, no adjustments. I loaded all seven into a magazine, inserted the magazine, hit the bolt release and it slammed home and locked into battery. I cycled the action manually through all seven rounds and every one of them ejected easily and the next loaded and locked.

Go figure. I'll try to hit the range again tomorrow.

[drjaydvm]

I had the same problem with some of the brass I made from 5.56 brass. I use a Sheridan case gauge now and test the brass after sizing and after loading. Anything that doesn't easily drop in and out I save for plinking in a handi rifle. You fire formed your cases to you chamber- that's why the second loading went better.

[Rich@CCC]

I see what your saying, but; these all measured below spec. Everyone of them should have dropped into a case gauge, no problem. I thought it possible that my chamber might be out of spec(and that may still be the case) but I think it more likely that I had some kind of blockage in the chamber that worked loose and the problem self repaired. If I'd spent a little time cleaning the bore and chamber before test firing, I'd have probably not had any problems at all.

[Trigger]

Rich,

Try seating the bullets deeper into the case. As long as you are not at max charge/max pressure. Your loaded rounds could be engaging the rifling before the round is fully chambered.

I seat mine deeper so the bullets do not bear on the ribs inside the magazine, as seen in your photo above. 2.050-2.100"

[GuanoLoco]

Not an expert, but:


LC brass should be good from a case neck thickness perspective.
Use a Lancer Mag vs. a PMag.
Load shorter.
Consider a Sheridan slotted case gauge: https://ballistictools.com/store/sheridan-engineering-300-blk-slotted-gauge

[Rich@CCC]

I thought I might have feeding issues because of the way the bullets were riding the mag ribs but that did not seem to be an issue.

I really have no way of knowing for sure what my pressures are as there is no published data on these components. I don't think I'm compressing at this length and my charge should be on the lower end by my calculations.

It does not look like the bullet is hitting the rifling but I'll check the lead just to be sure.

Like I said, the seven I just loaded seat and lock manually just fine. I'm going to hit it with a chamber brush and scrub the bore before I shoot it again. Just in case.

[Trigger]

Magpul has designed a modified version of their PMAG specifically for 300BLK. I think I recall the press release addressing changes to the interior ribs to allow full-length rounds (2.25") to load better.

This becomes a safety issue as well. Normally one cannot load a 300BLK into a 5.56 chamber if they are both loaded to 2.25" But by loading 300BLK so short that it stacks properly into a magazine, it becomes possible to mistakenly chamber 300BLK into a 5.56 rifle and fire it. Which destroys to rifle and causes injury. So don't reduce your OAL so much that this becomes possible. And buy some of Magpul's new magazines when available.

[GuanoLoco]

I have a 300BLK pistol that will chamber some of my reloads just fine and a 300BLK rifle that chokes and really doesn't want to go into battery on the same loads. Chambers vary.

Also, I use Pmags for 223 & Lancer mags for 300BLK. Keeps things simpler.

[JM Campbell]

I have a 300BLK pistol that will chamber some of my reloads just fine and a 300BLK rifle that chokes and really doesn't want to go into battery on the same loads. Chambers vary.

Also, I use Pmags for 223 & Lancer mags for 300BLK. Keeps things simpler.

I've found the lancer mags to be more forgiving on oal. Sample of 6. Wilson combat does have modified lancers 7.62x40 for their proprietary round that works very well with long loads.
ETA
Lancer modified mags
http://shopwilsoncombat.com/mobile/Magazines/products/416/

DH modified mags
http://shopwilsoncombat.com/mobile/AR-Style-Magazine-300-Blackout-30-Round-DH/productinfo/TR%2DDHMAG30%2D300BLK/

Sent from my iPhone using Tapatalk

[Rich@CCC]

This thing is going to drive me nuts!

I checked the lead on my chamber and I am far short of the ogive contacting the rifling.

I loaded up several different charges and hit the range today. The original seven rounds from the first loading all chambered, fired, and cycled fine. The rest did not go so well. Out of 15 rounds, 4 chambered and fired. I did not try to force them this time. I just came back to the shop and measured them. Every one of them measured below SAAMI(as listed in Lyman's 50th) spec in all dimensions except distance from base to shoulder and all of those were dead on spec. I then loaded all the rounds that would not chamber at the range into the same magazine I used at the range and every one of them chambered and went into battery by dropping the locked bolt with the bolt catch/release.

I'm going to have to pick up a chamber gauge, unless one of you fine gentlemen have one you'd be willing to loan out. I'd pay shipping obviously.

I will get a case gauge. I don't believe for a second that any of these would not drop right in, unless the printed spec. in the Lyman manual is wrong. The Lyman data matches what I could find on the interwebz from SAAMI +/- .0001".

[Rich@CCC]

BTW, Just to be clear, I am using a Lee Precision full length resizing die to form these cases. I could not find a true forming die anywhere. I may go ahead and buy an RCBS small base resizer and give that a shot. I hear they are closer to the bottom end of spec than Lee.

[Odin Bravo One]

Rich, it's hard to diagnose without seeing the components and rifle. At least for me. I'm a visual dude. If you're attending the TLG Memorial shoot, I'll happily bring my tools, gauges, and what not to take a look. Could also be that aspects of your load are just not agreeable with your rifle/pistol....... and/or vice versa. Knowing we all try to build as cheap as we are comfortable with, and having been in the BLK game for awhile now, I can say I've seen a lot of variation in parts and components for both guns and handloads. It only takes one item to be FUBAR to throw everything off.

FWIW, I've had issues with Pmags of various Generations functioning even my factory loads. I have a surplus of HK mags from back when they were free and they are very forgiving of the COAL and functioning in my rifles. BLK specific Mag bodies and followers have helped more than a few people with feeding issues.

Still, I'm afraid without being able to see and measure all elements in the equation, I'm afraid you're gonna be stuck playing detective one item at a time until the culprit is found. If you change more than one thing at a time, you'll never find out WTF is going on with your set up.

[Mike C]

Rich, it's hard to diagnose without seeing the components and rifle. At least for me. I'm a visual dude. If you're attending the TLG Memorial shoot, I'll happily bring my tools, gauges, and what not to take a look. Could also be that aspects of your load are just not agreeable with your rifle/pistol....... and/or vice versa. Knowing we all try to build as cheap as we are comfortable with, and having been in the BLK game for awhile now, I can say I've seen a lot of variation in parts and components for both guns and handloads. It only takes one item to be FUBAR to throw everything off.

FWIW, I've had issues with Pmags of various Generations functioning even my factory loads. I have a surplus of HK mags from back when they were free and they are very forgiving of the COAL and functioning in my rifles. BLK specific Mag bodies and followers have helped more than a few people with feeding issues.

Still, I'm afraid without being able to see and measure all elements in the equation, I'm afraid you're gonna be stuck playing detective one item at a time until the culprit is found. If you change more than one thing at a time, you'll never find out WTF is going on with your set up.

Not to thread drift but if ever you had the time Sean M it would be epic to see a thread with some of your general notes, thoughts and observations in running/maintaining a 300BLK carbine. It would be good even if it was just a short list of what components are optimal or sub optimal based on your observations and experience.

[GuanoLoco]

This thing is going to drive me nuts!

I checked the lead on my chamber and I am far short of the ogive contacting the rifling.

I loaded up several different charges and hit the range today. The original seven rounds from the first loading all chambered, fired, and cycled fine. The rest did not go so well. Out of 15 rounds, 4 chambered and fired. I did not try to force them this time. I just came back to the shop and measured them. Every one of them measured below SAAMI(as listed in Lyman's 50th) spec in all dimensions except distance from base to shoulder and all of those were dead on spec. I then loaded all the rounds that would not chamber at the range into the same magazine I used at the range and every one of them chambered and went into battery by dropping the locked bolt with the bolt catch/release.

I'm going to have to pick up a chamber gauge, unless one of you fine gentlemen have one you'd be willing to loan out. I'd pay shipping obviously.

I will get a case gauge. I don't believe for a second that any of these would not drop right in, unless the printed spec. in the Lyman manual is wrong. The Lyman data matches what I could find on the interwebz from SAAMI +/- .0001".

You don't want just any case gauge - you specifically want the Sheridan slotted for this.

SAAMI spec is fine and good but your chamber is what it is - and I have seen significant variation in my sample size of 2. Try seating the bullet deeper.

[Rich@CCC]

Sean,
I'll bring the pistol to VA next week. I wasn't going to ask, but I sure do appreciate your help on this.

GuanoLoco et al,
I picked up a box of Selier & Bellot sub sonic, 220gn cartridges today and they feed and chamber fine manually. But then so do my hand loads that refused to go into battery yesterday.

The diameter at the shoulder is about .003 greater on my hand loads than the S&B cases. SAAMI Spec is .361", mine measure .360" and the S&B cases measure .357". That is the only measurable difference I can detect. Other than COAL and mine are shorter with lighter bullets. My loads are .17" from contacting the lands.

If all I have to do is get a tighter sizing die for the initial form up, I'll be a happy camper.

GL,
Just out of curiosity, how would the Sheridan slotted gauge be any better than any other drop in gauge? It can't match my chamber specifically.

[Mike C]

BTW, Just to be clear, I am using a Lee Precision full length resizing die to form these cases. I could not find a true forming die anywhere. I may go ahead and buy an RCBS small base resizer and give that a shot. I hear they are closer to the bottom end of spec than Lee.

Rich, I think you might be onto something with the small base die. Not saying your barrel couldn't be out of spec because that isn't out of the realm of possibility but I do question surplus 5.56 cases converted to 300 BLK especially if they've been run through a 249. Out of curiosity did you source the brass from once fired from your own gun in 5.56 or is the brass converted from a CO using a surplus supplier? Additionally, have you tried resizing and reloading any factory once fired 300 BLK brass? Is the result the same? If you aren't contacting the rifling and you don't have a way to spec the chamber this might be an easy way to narrow down your problem without running out and buying a small base die or gage.

[Rich@CCC]

I'm using LC brass bought once fired and reloaded 2-3 times and run through my 5.56 ARs. I did not anneal the brass before reforming. I'll be adding annealment to the process as soon as I prove the concept.

[Mike C]

Blew my theory out of the water. With that I wouldn't waste my time with a SB die. I think your best bet is to have Sean M look at it. Please keep us apprised though as I am very interested in what the resolution is. All I run now is 300 BLK so any data points I can pick up on possible issues and resolutions would be very helpful. Thanks for starting the thread and sharing the info.

[Odin Bravo One]

Rich can you also be sure to bring all of your load and velocity data? My chamber and H/S gage are out in temp loan, but I've asked for them to be returned by next weekend. I'll also bring a handful of different factory and handloaded ammo so we have a smorgasbord to work with.

[Rich@CCC]

My load and velocity data are pretty much non existent at this point. I know what I loaded but I cant get the gun to run and haven't chronied anything. I shouldn't say the gun won't run. It runs fine when the ammo chambers. I haven't really even started to work up a load yet. I was just using up the Lapua pills that have been collecting dust for years. My ultimate goal is to work up a subsonic load for hard cast(maybe coated) heavies. I'm looking at a 247 gr 4 cavity hollow point mold from NOE
http://noebulletmolds.com/NV/product_info.php?cPath=30_353&products_id=999

I'll bring some of the formed brass, what I have already loaded(not much), the little bit of S&B factory stuff I have and maybe load up another handful for comparison. I doubt I'll have the RCBS die by Friday, but it's possible.

[GuanoLoco]

Sean,
I'll bring the pistol to VA next week. I wasn't going to ask, but I sure do appreciate your help on this.

GuanoLoco et al,
I picked up a box of Selier & Bellot sub sonic, 220gn cartridges today and they feed and chamber fine manually. But then so do my hand loads that refused to go into battery yesterday.

The diameter at the shoulder is about .003 greater on my hand loads than the S&B cases. SAAMI Spec is .361", mine measure .360" and the S&B cases measure .357". That is the only measurable difference I can detect. Other than COAL and mine are shorter with lighter bullets. My loads are .17" from contacting the lands.

If all I have to do is get a tighter sizing die for the initial form up, I'll be a happy camper.

GL,
Just out of curiosity, how would the Sheridan slotted gauge be any better than any other drop in gauge? It can't match my chamber specifically.

The guages I've seen only help with setting the shoulder and maybe OAL. The slotted gauge lets you see where the round is hanging up in the gauge. I think it is designed to help with diagnosing such issues.

If you are confident that you aren't in the lands then suggest pushing the shoulder back a little further. Manufacturers quickly learn to set up so that their ammo works in the largest # of guns.

Long shot - make sure there aren't any dings or deformities on the base of the case. This can usually be quickly fixed with a file.

[Odin Bravo One]

My load and velocity data are pretty much non existent at this point. I know what I loaded but I cant get the gun to run and haven't chronied anything. I shouldn't say the gun won't run. It runs fine when the ammo chambers. I haven't really even started to work up a load yet. I was just using up the Lapua pills that have been collecting dust for years. My ultimate goal is to work up a subsonic load for hard cast(maybe coated) heavies. I'm looking at a 247 gr 4 cavity hollow point mold from NOE
http://noebulletmolds.com/NV/product_info.php?cPath=30_353&products_id=999

I'll bring some of the formed brass, what I have already loaded(not much), the little bit of S&B factory stuff I have and maybe load up another handful for comparison. I doubt I'll have the RCBS die by Friday, but it's possible.

Hopefully we can shoot it on the range. I'll bring some of my loads and a variety of factory loads to test. I'm guessing the issue is with your LC Converted brass. But that's just a guess.

I'll bring my sizing die and hand press too.

[Rich@CCC]

I just loaded up 20 of the 178 pills at 13gr CFE BLK and 18 chambered fine, 2 did not go into battery. I separated them for comparison.

I think you are correct in that the issue is the Lee sizing die was just not meant for forming new brass. The interwebz consensus is the RCBS SB die is the best non forming sizing die for the job.

[Rich@CCC]

I just polished the base of the Lee full length resizer with 2000grit and Berserker Blue. Maybe removed .0001(maybe not). There was a small imperfection and a visible concentric ring on the base that are now gone and it's polished to a mirror finish so there was definitely a bit of material removed. My measuring equipment is not that precise. This should effectively bump the shoulder a tiny bit.

I'll load another 20 rounds with the polished die later and bring those along as well.