Apex/ Barsto barrel M&P 9mm

[agksimon]

I have a fairly decent set of gunsmithing and machining tools and have installed countless Apex trigger kits and sights for our IDPA group and friends. I'm looking forward to this new challenge, if the opportunity presents itself. I just want to see if the Apex installation is superior enough (smaller group sizes), to make it worth sending in. I purchased a Storm Lake drop in barrel for my M&P 9mm Compact earlier, this year and had some undesirable results. First; it didn't improve the group sizes, despite trying many bullet weights and factory brands, including a few home brew. Second; I found out that Winchester white box 115 grain is at the long end of spec and the gun would not eject live rounds once chambered and I had to remove the magazine and drop the cartridge out the mag well to remove it. Not good when shooting an event and having a dud round, plud it's a safety issue too.
Needless to say, the barrel went back for a refund.

One more question Randy: If I fit the barrel tight to your specs, at room temperature and it runs fine, then dump a few mags through it and it warms up, will there be enough expansion to cause a problem?

[Randy Lee]

I have a fairly decent set of gunsmithing and machining tools and have installed countless Apex trigger kits and sights for our IDPA group and friends. I'm looking forward to this new challenge, if the opportunity presents itself. I just want to see if the Apex installation is superior enough (smaller group sizes), to make it worth sending in. I purchased a Storm Lake drop in barrel for my M&P 9mm Compact earlier, this year and had some undesirable results. First; it didn't improve the group sizes, despite trying many bullet weights and factory brands, including a few home brew. Second; I found out that Winchester white box 115 grain is at the long end of spec and the gun would not eject live rounds once chambered and I had to remove the magazine and drop the cartridge out the mag well to remove it. Not good when shooting an event and having a dud round, plud it's a safety issue too.
Needless to say, the barrel went back for a refund.

One more question Randy: If I fit the barrel tight to your specs, at room temperature and it runs fine, then dump a few mags through it and it warms up, will there be enough expansion to cause a problem?

I expect our SDI to perform 85-95% of what our Gunsmith Fit barrels will do. This is because our GF barrel will compensate for variations in slide to frame fit 100% of the time. The SDI, as the name implies will compensate for vertical lock up variations roughly 90% of the time. The missing 10% out there have slide to frame vertical tolerances that are so far out on the acceptable range that only a GF barrel can be used to remedy the situation.

Thermal expansion shouldn't be an issue. If the barrel is properly fitted, even to a snug fit (slide will go into battery with 4 lbs or less of pressure applied to the back of the slide) it should still cycle. That is assuming the gun has proper lubrication and a factory recoil spring that has been replaced at the armorer recommended maintenance interval.

[Luke]

Any news yet?


Will these barrels be fine in a 9 major gun? Just thinking out loud

[Randy Lee]

Any news yet?


Will these barrels be fine in a 9 major gun? Just thinking out loud

If all goes well, you should see barrels before Thanksgiving.

While the case is fully supported, I would not recommend 9 major.

The barrel in 356 TSW is a different story... 😄

[agksimon]

Any news yet?


Will these barrels be fine in a 9 major gun? Just thinking out loud

Please explain the difference in a regular 9mm barrel and a major.

[Luke]

Please explain the difference in a regular 9mm barrel and a major.

I'm not really qualified to answer that because I don't really know. I just know 9 major produces a lot more pressure and some barrels are not ok with that. Be it material, thickness..idk. I just know there are some you do and some you don't. Hope this has helped

[Lomshek]

Please explain the difference in a regular 9mm barrel and a major.

Dimensionally the same. 9 Major is just hot rodded way beyond SAAMI spec's.

[Luke]

I thought he was talking about the barrel differences and not the round it self, just to clarify.

[Randy Lee]

9mm Major is something that has been relegated to IPSC open division pistols. Competitors are essentially pushing the 9mm case beyond the limits of established SAAMI pressures. That is why you do not see commercially available ammo at your local WalMart- it is too easy to have someone fire a 9 major round in an unsupported barrel with potentially catastrophic results.

The 9mm cartridge max pressure is around 35,000 psi if I recall correctly. I don't know if anyone has tested the MAP on 9mm Major.

For myself, I am planning on resurrecting the 356 TSW round, since it's case was designed around 50,000 psi max with the same cartridge OAL as the 9mm Luger. Think of it as .357 Sig ballistics but with the magazine capacity of a normal 9mm. Smith and Wesson had a good idea with this cartridge, but they dropped the ball in their marketing strategy...

[Savage Hands]

Are you looking to do Glock barrels as well Randy?