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.45 Gap

3149 Views 10 Replies 7 Participants Last post by  jonm61
Hello, I am new to this. I have a glock 37 and started reloading. Can I trim down .45 acp brass and use it for .45 gap? I know the acp case is taller, but would it be a problem? Would appreciate any and all insight.
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Welcome to the forum Jackson. Enjoy!
try it, also the acp has a lager primer than the gap, everything else is the same
I too am new to reloading so please take what I have to say with a grain of salt.

Purchase a reloading manual from the folks that either produce the GAP load or from a bullet maker that loads what you need. Follow their instructions when it comes to components to a tee.

Their information is designed around the components and the powder that they use. From what I know, it is not wise to swap out stuff like primer sizes because of several factors.

My best information I can guide you with, under my limited education in reloading is too search high and low for the information you seek and apply it wisely if you know what I mean.

GLOCK makes a very forgiving weapon but even it can only do so much.

Because the GAP charge is small I believe it is usually charged with a very fast burning powder. It hasn't much time to get that projectile moving and the gases have to get max. push in that short distance.

If you were to put a large primed(Larger flash) cartridge in there that is usually used for slower burning powder you may be exceeding the chamber pressure, but that is purely spectulation on my part as I know nothing about that particular cartridge in the way of components.

You are doing what you can by asking here but I would want to weight several options before trying a large primer cartridge in my gun. I just had another thought too.

The cartridge head may be of different diamenions internally (reducing charge size) and look for the ejector to possibly strike the larger primer during the ejection process. The groove for the extractor may/may not fit up either.....

Best wishes and be safe. I think if it has been figured out, it is on the internet somewhere!
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Thanks for the help and the welcome everyone.
I'm not sure, but I would just buy GAP brass personally. If GAP ammo used large pistol primers like ACP, then yes. Because they don't, unless you can find a reloading recipe that is written specifically for using trimmed ACP brass, I wouldn't do it. It's too easy to make a mistake.
I won't say for 100% sure but I could have swore that on the StarLine site is said that that the 45GAP used small pistol primers. That's probably true since they had to go with small pistol primers on the 40S&W so that the primer wouldn't hit the ejector on the 9mm size guns it was to be used in.
The GAP sounds interesting but I've got over 1100 rounds of 45acp on hand so personally, if it were me I'd just stick with the ACP since you can find it just about everywhere and it has a proven track record and the guns really aren't all that much larger then the GAP guns IMHO.
I won't say for 100% sure but I could have swore that on the StarLine site is said that that the 45GAP used small pistol primers. That's probably true since they had to go with small pistol primers on the 40S&W so that the primer wouldn't hit the ejector on the 9mm size guns it was to be used in.
The GAP sounds interesting but I've got over 1100 rounds of 45acp on hand so personally, if it were me I'd just stick with the ACP since you can find it just about everywhere and it has a proven track record and the guns really aren't all that much larger then the GAP guns IMHO.
I can't see the comparison. Size does matter and smaller is better in this case.
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I should clarify everyone. I meant I was new to this forum. I have reload before. Lee precision says to use a large primer, lyman says small primer. Some 45 acp rounds use small and large primers. I was just curious to find out if i trimmed the acp round down and maybe used less charge. Maybe it could be a plinking round. I know ammo was easier when i found it before the Obama scare. It still has significant power for a smaller round. Also the pressure is the same at 23,000 with the +P rounds in a normal 45 round. I am saving to get a 10mm. I already have a 1911 and the gap rounds feed and shoot nicely through it. Thanks everyone for the input.
All of my .45GAP rounds use small primers...I've never seen any ACP that does, but I'll take your word for it.

And yeah, .45GAP is, essentially, loaded like a .45ACP+P from everything I've read.
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