As you may already know, Swift A-Frame bullets have deep cannelures that look more like a groove or channel. I am in the process of developing a handload with these bullets, and the edge of the case mouths end over the cannelures, but with enough room to crimp the cases.

I will be using RL-19, Winchester brass, and CCI 250 primers to produce a velocity of perhaps 2,560 to maybe 2,600 fps, but I am wondering if crimping the bullets would greatly increase chamber pressures. My rifle has a fast barrel, so it is possible to reach the desired bullet speed before I reach high powder charges.

Yes, I already handloaded the first batch of ten so I plan to test them tomorrow, but I would like to hear your comments on what you have experienced when crimping ammo.

[ 06-11-2002, 07:53: Message edited by: Ray, Alaska ]

Well...I found some information that relates this subject, not necessarily on chamber pressure increase because of crimping, but instead on possible accuracy gains from crimping. This data can be found right here in this forum at: http://www.accuratereloading.com/crimping.html

Ray,

I shot my M98 conversion in .358 Norma off the bags last weekend with worked-up loads for the 280gr Swift.

They were crimped and from the looks of the tip of that bottom round when its turn came up it's a good thing it was crimped.

Shooting offhand would most likely even increase bullet set-back.

It shot 2MOA which is good enough for elk but I'm still going to try another couple of powders. (Maybe even a different bullet, but I'm definitely a heavy-for-caliber believer)I'd like to see 1.25 MOA or better.

I'd also like to see not getting a scope to the bridge of the nose, so I'm looking to put a M8 2.5x on it, instead of the 2-7x that "kissed" me.

Ray,

I use Swift A-Frames in my .375, and I don't crimp. Neck tension is sufficient to keep the bullets from moving during recoil.

Try shooting with a full magazine; don't fire the last round. Compare COAL between it and a round that has not been put in the gun.

George

On the .338RUM, I might consider crimping. On the A-Frame, my results actually improved a little with a small crimp. Remington does from Factory ammo. I can't say I have ever had any bullets back out, but I did anyway.

Thanks for the replies.

I will have to shoot the first group of ten in the near future when it stops raining. What I will probably do is to see how the crimped batch shoots, then try another batch without crimp and select the better shooting one.

When I crimped the cases I was surprised of how much the mouth edges rolled into these cannelures. These cannelures are deeper than what I am accustomed to.

[ 06-12-2002, 06:29: Message edited by: Ray, Alaska ]

Never crimp if it isn't necessary to keep the bullets from moving due to recoil or use in tubular magazines.

Ray,
A light crimp won't change or hurt anything, but I don't crimp my 338 with those bullets or the 300 gr. Woodleighs...

One could feasibly turn a couple of thousands off his resizer button and as you are using a bulky powder that pretty well fills the case you would be about as well of as with a crimp....I do this with most of my big bores but never had to with a mild recoiling 338...

Thanks again for the replies. I don't think I am going to crimp the next batch. In fact, I feel the cannelure on the 275-grain A-Frame is too deep.

As Ray said, the bullets are pretty much seating on the powder, and the Redding dies I use have always expanded the neck of the cases just enough to provide a solid grip on the bullets.

I say crimp if it makes you feel better. I crimp "ala Lees crimper" for my .375 A-frame loads. I mean how many of these bullets am I actaully going to shoot on a hunt ? Even if I go to Africa Im a pretty conservative shooter and it doesnt often take more then one shot per critter.

I crimp and even waterproof my hunting loads. I know its silly but it does make me feel better. Frankly it would take me 10 lifetimes to shoot all the crap Ive loaded. Reloading is my faveorite hobby, give 'er a crimp and see how she shoots. a lot of things can happen in the Alaska wilderness........good hunting...........J

I shot the 10 crimped rounds at the range today. 69 grains of RL-19 behind the 275-grain A-Frame clocked an average speed of 2,570 fps.

I also shot some with 68 and 68.5 grains, then up to 69.5 grains, but the best group was with 69 grains of powder. This powder charge produced a good group right in the center of the target, while the other ones printed about 2" to the left from center. 69.5 grains of RL-22 was producing over 2610 fps. RL-22 with the 275-grain Swift should give me higher velocities than RL-19, but since I was seeking a velocity under 2600 fps I will stop at 69 grains of RL-19.

The crimp on the cases didn't seem to be a problem, so I will crimp the next rounds, except that the crimp will be very mild instead of what I did before. Thanks to all of you for the responses to my question.

Ray,
The only time an uncrimped round will cause problems is when its left in the gun and many rounds are fired off the top of it, such as in elephant culling when one is trying to keep his gun full at all times...and that's providing the dies and everything is correct.

A light crimp is always perfectly acceptable in a big bore gun.

Thanks, Ray.

Someone I know in Canada uses a couple of .338's for hunting deer to moose-size game. He uses bullets around 180-grains for small game such as deer, and the 225-grain Swift A-Frame for large game. He is an avid reloader, and has developed handloads so that a lightweight .33 bullet can match the POI of the heavier one. He just killed a grizzly a week or two ago with one shot from his .338.

The following is part of his e-mail: "At about 11:00 a.m. we drove into the last new area off the main road where we hadn't been before and this road led into the mountains up
high which didn't show up on the maps. The snow was still on the ground in spots and the grass was just starting to grow. We drove up into the high slashes and there in one small area was this grizzly. We watched it until
it decided we were a problem and started to leave by walking right across the road in front of the truck about 75 yards out.

My partner shot it first with a 7mm Rem Mag and a 150 Sirrocco on the road because he was in the passenger seat with his rifle and could get out sooner than I could. When hit, the bear jumped into the slash on the far side of the road and started for a nearby hillside which gave me time to get out of the truck, load my rifle, and line up over the hood of the truck for a rock steady shot. The bear had traveled to about 170 yards by then. When I
shot, the 225 Swift simply flattened it and it was over."

He has developed handloads using bullets that some .338 deer hunters may be interested in knowing. He has also tested the bullets by firing them into wet phone books that have been immersed in water for a few nights, firing from 50 yards to about 200. The 180-grain bullets develop from 2,900-3,000 fps at the muzzle. I am going to ask him for permission to post the results of his tests.

[ 06-16-2002, 22:31: Message edited by: Ray, Alaska ]