Crimp Groove on an Auto Boolit

[jonp]

On a different thread, Crimpin on the groove, I posted a comment about crimping the boolit into the crimp groove using it as a depth gauge and putting a slight taper crimp on it so it headspaces correctly as the question was about a crimp groove. A couple of people commented that they had never seen a crimp groove on an auto boolit and I guess this is the first ones I have bought that have them but didn't realize it so I thought I would post a picture of the boolit and ask "Is this indeed a crimp groove"?

68711

Missouri Bullet Company IDP #4-XD 200gr RNFP .452
It sure looks like one to me.
BTW: I works great seated into the "crimp groove" in my Kahr over 4.2gr of Promo.

[GabbyM]

Yes it is a crimp grove. That is the Magma 45-200-rnfp. Good for both revolvers and 45 acp. Usually works well in the acp when crimped slightly into the grove. You need to hold your dimension on the case mouth. For head space.
acp dies I have (Dillon) does not have a seat plug that centers the rnfp very well. You may wish to modify your plug with epoxy or get a revolver seat plug. Just make sure you can get the bullets straight.

I have that mold btw. It's a great shooter in acp and smacks hard.

[RobS]

Yep....crimp groove on a 45 ACP boolit as it is more than likely meant for a 45 Colt. This doesn't mean the boolit can't be used for the 45 auto though. I actually designed a 45ACP/45 Colt boolit for my needs and it's running in at about 225 grains. Very accurate in the ruger flat top 45 revolver with either the 45 Colt cylinder or the 45 ACP cylinder and the design does very nice in the 45 colt lever action rifle as well as in the 45 ACP pistol.

http://www.accuratemolds.com/bullet_detail.php?bullet=45-225B-D.png

I don't crimp in the crimp groove for the auto as I designed it to be crimped about in the middle of the front drive band.

[RobS]

Missouri Bullet Company IDP #4-XD 200gr RNFP .452
It sure looks like one to me.
BTW: I works great seated into the "crimp groove" in my Kahr over 4.2gr of Promo.

What is your COAL with that boolit design?

[jonp]

I'm running it at 1.173 and taper crimping it to .474. Goes in with just a little push.
BTW: MBC markets this boolit as being designed specifically for a Springfield XD. I also checked some Berrys Boolits also in RNFP and 200gr that I haven't used yet and they look identical to these, crimp groove and all.
Guess the question which I didn't think of when ordering them was why if it was for an XD it had a crimp groove?

[deltaenterprizes]

I believe that is a design for the 45 long Colt to be used in lever actions in cowboy action shooting with low recoil.
It may work in 45 ACP but should be taper crimped since that is what the designer of the cartridge and firearm intended.
I also think the bit about the design being for the XD is a marketing technique, a call to Magma can establish the truth of this claim.

[35remington]

Since max SAAMI spec for case mouth diameter in 45 ACP is .473" the case mouth should be crimped to at or below that figure. Most use around .471-.470" or so as an average, as this crimps both short and long cases and turns the case mouth flare in.

[jonp]

I have not tried it at .473 or below as .474 works in mine although it is .001 over published. I have been working up seating depths and charges of Promo and have not got to crimp yet.
I'm curious as to what the 2 people who voted no on crimp groove think it is

[KYCaster]

I'm running it at 1.173 and taper crimping it to .474. Goes in with just a little push.
BTW: MBC markets this boolit as being designed specifically for a Springfield XD. I also checked some Berrys Boolits also in RNFP and 200gr that I haven't used yet and they look identical to these, crimp groove and all.
Guess the question which I didn't think of when ordering them was why if it was for an XD it had a crimp groove?



That mold has been in the Magma catalog for at least 20 years. The note under it says "Long Colt".

I just ignore the crimp groove, unless the case mouth happens to fall in the middle of the slope in the groove. In that case, just seat the boolit in or out another .020, which ever feeds better in your gun and work up the load at that length.

Jerry

[243winxb]

why if it was for an XD it had a crimp groove? The XD may have a tight throat/leade needing a .451" diameter bullet. Some Lee RN bullets need to be seated to a shorter than normal COL to fully chamber. Measuring on the bullet right in front of the case mouth, bullet diameter should be .450" to always chamber. The crimp groove has nothing to do with it, its for a Colt. IMO.

[ku4hx]

I've loaded boolits like that in 9mm and seated it so that the case mouth is a hair above the crimping groove. They were 125 grain .38 Special/.357 Magnum TC boolits and worked well in my Glocks, wife's SR guns and my BHP. Cartridge OAL was not a problem.

[GabbyM]

I load that Magma 45-200-RNFP in 45 acp to where the case mouth is just under the top edge of the crimp grove. Taper crimping into the grove. That way case length variation has less effect on crimp pressure. Don't actually crimp them just turn the mouth back in to meet O.D. requirements. .469" to .470". Charging 5.6 grains of HP-38 makes major. As far as I can tell they shoot as well as my H&G #68 SWC's. It's just that my Dillon seating die has a double ended stem. One end is a fit for the H&G SWC so you get a straight bullet every time. The flip side is cut for a government profile jacketed RN. This RNFP doesn't fit up into it well but you could use the epoxy trick or I'd think buy a 45 Colt seating stem to use in the ACP die.

[jonp]

2 things: I understand about not needing the groove on auto's but thanks for remindinding me and everyone, it's a pretty important thing
Are you saying to go to the groove and then just crimp to .470-.473 ignoring it? Will this give enough tension to hold the boolit in place?
Ok, a third one: this is a "re-purposed" boolit originaly for a 45colt so that explains the crimp groove.

[RobS]

2 things: I understand about not needing the groove on auto's but thanks for remindinding me and everyone, it's a pretty important thing
Are you saying to go to the groove and then just crimp to .470-.473 ignoring it? Will this give enough tension to hold the boolit in place?I typically adjust my COAL to where the round chambers and cycles well and then I crimp as little as possible which is typically in the range of .470-474 with most of the time being at 472-473. If you are sizing the brass with a proper sizing die for 45 auto then the case tension is all you will need to keep the boolit in place. The crimp is typically only needed to take the bell out of the case..
Ok, a third one: this is a "re-purposed" boolit originaly for a 45colt so that explains the crimp groove.
Yes, a design with initial purpose as a revolver boolit but can be used well in the 45 ACP