? on 40 S&W + P ammo

[platoonDaddy]

Since there is no SAMMI specs for 40 S&W +P ammo, what specs is Buffalo Bore, Georgia Arms & Underwood using for their 40 S&W +P ammo?

[GregP220]

Dunno, but I'm not going there with my 40s.

IF you want to run a super hot 40 just get a 10mm....

[Ttwwaack]

I was reading some time ago in Reloader magazine about the confusion of SAMMI Standard anrd +P. If the ol gray matter recalls it correctly, it is only a 10% raising of the pressure in CUP or PSI. Take 38 Special for example, the standard reguardless of bullet weight is 17,600 cup. +P pressure was standardized as 20,600 or about 15% more.

There is no shortcut recipe to velocity without adding pressure. The only thing that is happening is that manufacturers are playing with primers and new powder combinations to get a repeatable results. An example would by that ABC Reloaders decided to re-invent the 32 ACP for the SD market. They went to Starline and bought a production run of all the same brass and enough primers, powder and bullets: again the same lot from each manufacturer. Then the mad scientist put his hat on and came up with a recipe and sent off samples to either the powder manufacturer or a private lab for testing. If it meets SAMMI Spec they can retail it to the public without further problems/liability and be able to fight the lawyers in court with documented testing in the event someone comes a calling cause their shit blew up.

There is not much difference between the 10mm and the 40 S&W pressure wise. The 10mm is able to attain more velocity at the same pressure or a little elevated over the 40 is due to the initial OAL.

40 S&W = 36100 psi. 40 S&W +P = 39710 @ 10% and 41515 @ 15%

10MM Auto 38700 psi

When I was working up loads for my G20 I did quite abit of reading over @ Glock Talk in the 10mm sub-forum in the reloading section. Do a search of threads and posts by McNett. He is a boutique ammo manufacture and listen carefully, take head and realize that shit happens fast at the pressures your working at.

Some things that I noted for 10mm loading were:

- Factory and aftermarket chambers, upping recoil springs to prevent early unlocking and reduce extreme velocity spreads
- Full house rounds get loaded in virgin brass. Once fired brass sans smileys can be regulated to sub-nuclear practice loads but no more racing for that case.
- CCI LP Mag primers only.
- Do load development with a chronograph to look for velocity stalling.
- Get enough supplies of the same lot to ensure uniformity during testing. You run out of something, start over and prove your recipe.
- Make maximum .2 grain elevations in powder charge during testing. If using flake powder, hand weigh each charge.
- If throwing charges, confirm accurracy and consistancy of thrown charges and individually weigh each charge if results aren't spot on.

To save on magazines, mag springs, base plates and followers; remove magazine after loading the chamber to give the gasses someplace to go unimpeded. Also a pair of gloves might also be a good idea to go with the safety glasses you'll be wearing.

There is also the poor mans ballistic lab... it is a process which uses a known standard and compares it against itself. To perform this test find a couple of boxes of good factory shells. Shoot 10-20 rounds and measure the case swelling at the base of the web with a micrometer to .0001. Take another ten rounds and take them apart and re-assemble with your load (primer, powder and bullet). Shoot those and measure to compare against the factory ammo standard. It is not precise, but it gives you an idea of where you are at. Using once fired brass is a no-go since it work hardens so quickly and each batch of brass has its own charactoristics..

Afterthought: If your platform of choice is a 1911 and you don't have G10 micarta grips, get some.

[platoonDaddy]

Ttwwaack Thank you, very educational!

[Ttwwaack]

Sorry for the mis-information, Glocktalk caliber specific loading Info is under the 'clubs' subforum. Here ya go... http://glocktalk.com/forums/showthread.php?t=1452421

They appear to be pushing them pretty hard...

ETA: Stopped by the local fun store and saw some Buffalo Bore 40 S&W +P on the shelf. The packaging had the velocity advert as 1100 for a 180 gr pill. Not that far outta line and is easily attainable with 800x, Lshot and PwrP. Theres a guy over on GT loading 180s to 1300+ like it was a 10mm. That, I consider over the top.

[Bimmer]

There's a guy over on GT loading 180s to 1300+ like it was a 10mm...

Is this is in a "normal" .40S&W chamber?

I only ask because there are a lot of guys on Brian Enos' .40 forum loading .40 with extremely long OALs, (1.200" instead of 1.135"), but they're also using custom race guns with custom chambers. With that much extra space in the cartridge, turning up the velocity to 1300fps might not be so over the top.

[Ttwwaack]

Glock 22, 23, 27 and 36 with standard 40 S&W chamber in factory and aftermarket (kkm & lonewolf) barrels @ 1.13. Hit the link. I was getting guppies with 180s LTC, 800x in the vicinity 9f 1050 in a 229 that made me back off and finally pass on the 40 in favor of the 10 and 45 acp.

[bfoosh006]

Deleted