Newest Threads

duster066 · 04-27-2012, 04:31 AM

A post in the 10mm JCP thread got me doing a search for 45acp magnum. I discovered the 45 Super, Star Line brass, and load data. I bought my JHP because I wanted to see what all the HP hype was about and for no other reason. It now pretty much sits and collects dust, so you know where I'm going.

I've read here the barrel is 4140, and there is a bunch of material in the chamber area so I'm not to concerned about the barrel. Since I really don't care if a fun experiment wrecks the gun I am not concerned about the slide weight, but I'm assuming it will be enough to prevent a case rupture. However I would prefer to not wreck the gun so that brings me to the recoil spring. I found a sight where a guy did an $8 45 Super mod to a Kimber 1911. From the data he presented the heavier the slide weight the less increase in recoil spring rate is required, but there was no math and it probably wouldn't be applicable to a blow back design anyway. I suppose I could buy some spring stock from Midway and make a few springs until I found one that would not cycle then go back to the heaviest one that worked.

I'm looking for a discussion on the idea. I bought the gun to play with and this sounds like fun. And if it actually worked, albeit the costs is reduced life span, it would make my HP 45 a bear killer capable hand gun. I think I'm going to do this.

Please spare me the lectures about how dangerous it is. Life is dangerous unless you refuse to get out of bed, and that will kill you. I'm not stupid just adventurous and I have a gun I don't mind experimenting with.

**Ranger-6** · 04-27-2012, 04:55 AM

In a study of recoil springs, I found that heavier recoil springs mean slower rearward travel but faster forward travel. Such action does not seem to change cycle times. If a shooter was to use higher pressure cartridges, such as, Buffalo Bore: 45 ACP Super 230 grain 1100/618 JHP #45S230 then the main focus would be to reduce felt recoil.

The thought is when using high-pressure loads then use extra-power recoil springs. Reducing felt recoil allows a shooter to shoot faster follow-up shots. However, rather than using a heavier spring it might be better to use a secondary spring, a smaller spring inside the main recoil spring.

duster066 · 04-27-2012, 05:27 AM

You need a higher spring rate to slow the faster moving slide before it hits it's stop otherwise you will have slide or frame failure. I don't think a secondary spring will fit inside the stock spring as the recoil spring guide fits tight inside the stock spring.

I admit I haven't looked, but what limits slide travel on the JCP/JHP? Is it the recoil spring guide rod? If so it's also acting as a buffer and would get beat to death without a heavier spring.

Yes to the faster forward travel. A heavier firing pin spring is required to mod a 1911 for 45 super because the momentum of the faster forward travel overcomes the stock firing pin spring causing chain fires.

**Ranger-6** · 04-27-2012, 05:54 AM

The Recoilmaster incorporates a strong secondary recoil spring that engages after cartridge case ejection to cushion the shock of the slide against the frame and extend the recoil pulse over a longer duration.

http://www.gun-tests.com/performance/jun96recoil.html

**lklawson** · 04-27-2012, 02:06 PM

Sounds like a cool project.

We need lots of pictures.

Peace favor your sword,
Kirk

**lklawson** · 04-27-2012, 02:09 PM

Quick question: Is the chamber of the JHP fully supported? If it is then you may be good-to-go with just a heavier spring (or a more massive slide if you can figure out a safe way to add mass). If it is not fully supported then I predict case ruptures.

Peace favor your sword,
Kirk

**ThompsonCustom** · 04-27-2012, 10:20 PM

Quote:

Quick question: Is the chamber of the JHP fully supported? If it is then you may be good-to-go with just a heavier spring (or a more massive slide if you can figure out a safe way to add mass). If it is not fully supported then I predict case ruptures.

What he saided. the C9 is fully supported and I've run up to 60k psi with no problems. Good thing to do when testing the really high reloads tho is to shoot it from a vise or something so your not so close, just in case it does blows up which I don't think it will but it's always better to be safe then sorry. I've put my c9 through a lot of hard hitting reloads and never even upped the recoil spring and I don't think it shows any signs of wear but a recoil spring won't hurt anything as long as you can cycle the slide other than that have fun and be safe.

Something I seen in a gun magazine once that I thought was pretty neat was a guy loaded some 305gr .45acp bulllets if you could push these fast enough they would make some bear stoppers, but the weight and increase bullet length would raise pressure quickly so a little bullet still might be better idk I don't have a .45 to play with........yet.

duster066 · 04-28-2012, 10:59 PM

Quote:

Originally Posted by lklawson

Quick question: Is the chamber of the JHP fully supported? If it is then you may be good-to-go with just a heavier spring (or a more massive slide if you can figure out a safe way to add mass). If it is not fully supported then I predict case ruptures.

Peace favor your sword,
Kirk

I don't know if it is or not. I'm casting today and decided I want to have some range fun with the 45 so I'm dropping a bunch for it. I'll play with my loads and see how much more I can squeeze out of it. When I'm done shooting it I'll teat it down and look it over real good, then make a plan for a 45 super hi point.

Agreed about shooting it from a vise, that will be part of the plan.

Mortblanc · 04-29-2012, 08:37 PM

You are going to put your eye out!

Literally!

You start messing with those preasures and the polymer frame is going to turn loose of the nonferrous pot metal slide and take the side of your head off, along with fingers and chunks of arm.

You do not just put a new screen door spring in there and claim "good to go".

duster066 · 04-30-2012, 02:18 AM

Quote:

Originally Posted by Mortblanc

You are going to put your eye out!

Literally!

You start messing with those preasures and the polymer frame is going to turn loose of the nonferrous pot metal slide and take the side of your head off, along with fingers and chunks of arm.

You do not just put a new screen door spring in there and claim "good to go".

We'll see I assure you. I'm not worried about my head, fingers, hand, or anything else except the gun. No I'm not worried about the gun either, if it blows I've lost little and learned a lot and had a great time doing it. If you had read carefully you'd see it will have to go like a nuke to hurt me. Stay in bed.