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one of us |
I'm trying to work up a load for a .338 Lapua Mag. with 250 gr. Nosler Partions and Retumbo. This will be my prairie dog and squirrel load. During my first outing, I shot five rounds each of 92, 94, 96, 98 and 100 gr. of Retumbo. The groups were best at 94 and 100, so I now have loaded up five rounds each of 93, 94 and 95 gr. But here's my problem: there were no pressure signs at all at 100, so I decided to try 101 and, if still no signs, 102, so I loaded up five rounds of each. However, with both 101 and 102 gr., I got a distinct crunching sound of a compressed load. How am I doing, here? Am I risking anything going with a compressed load for a Lapua Mag? kk | |||
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| one of us |
No, you're not risking anything by running a compressed load in your Lapua. In fact I specifically try to find loads for my 338/378 that are right at the point of compression for maximum load density, and many of my favorites have been compressed loads that had the "crunch" when you seated the bullet  . The only problem you might be causing is going to be from going over the pressure limits but you already knew that. Otherwise, if the accuracy is to your liking, you're fine. | |||
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| one of us |
Quote: Long story. Actually, it's my boss's boss's gun. It kicked the hell out of him and scoped him, so I offered to help tame the beast. So far I have had him add a Pachmyer Decellerator, a muzzle brake and a Swarovski scope. (What the hell. He has money.) Now I am working up a load that will be accurate. I chose Retumbo exactly because it's slow, to try to drag out the recoil as much as possible. Seems to be working. His last session at the range he shot 20 rounds with no ill effects. Before the modifications, he got bruised with only five rounds. He still thinks it kicks a lot. Go figger. kk | |||
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| one of us |
Just so long as it doesn't bulge cases. Retumbo may prove too slow. Have you tried H4831? | |||
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Quote: I don't hunt deer. Too scary. kk | |||
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| one of us |
KK this sounds familiar. You posted about this a long time ago if I remember correctly. I think the gun was a Sako? You might also try H-870. It's probably going to be too slow to produce super high velocities but you can probably work up some slower loads to keep the recoil down a bit. I had to go back and edit this because I forgot something. If you're trying to reduce recoil you need to switch to lighter bullets. I worked up a load for my 338/378 using 200 gr. Nosler Ballistic Tips (they have 180's too). Not only is the recoil a fair bit less, but they accuracy is fantastic (it always is with BT's). Plus, they're cheap! My load is 104 gr. of RL25 and the BT's clock at 3400 fps. on the dot. I worked it up just for practicing but it's actually turned out to be a darn good whitetail load. | |||
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| one of us |
KK, I don't have a 338 Lapua but I have used AR2217 (H1000) in a 375 Rum & some of the loads are compressed. Yes they do crunch so its OK as long as you are not over max as per the manuals. I use a chrono to guage if I am at max or not rather than case head expansion. However, by using slower powder you are not going to reduce the recoil, in fact quite the opposite. In all the recoil formulas the weight of the powder charge is factored in as the "ejecta" has a recoil effect. In practice I have found it true as I slowed the 375 RUM down to 375 H&H velocities with AR2217 & the recoil still felt worse than a H&H going at the same speed. So if you are trying to cut down on recoil try using a faster powder & less of it. Regards JohnT | |||
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You think he'll be able to get over his flinching? | |||
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| <eldeguello> |
Quote: As long as the compressed load does not start bulging the case shoulder to the point where the round won't chamber, there's no particular problem. Some compression is usually a good thing, because it keeps the powder charges in a fixed spot, producing better shot-to-shot uniformity.  | ||
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Quote: That's the question, isn't it? I have explained three times to him how they eye is an infallible flinch point. Just flash your hand at somebody's face from two inches and they'll flinch. And he got scoped. At this point, the best I can do I try to reduce felt recoil and advise him to work out on smaller calibers. By shooting a target with his gun and the loads I provide, he will have a benchmark of what the gun can do. I'm not exactly a marksman, but I can hold for an MOA if the gun can. I really feel sorry for the guy. He loves the Lapua � or at least the idea of it � but needs coaching badly. In a company of 250 employees I am the only other person that hunts or shoots, so I'm the default guru. Everybody is a freaking golfer. So I am proposing a joint company outing called chip-and-skeet. Anyway, we're working on this Lapua project, and he has a September date with an Alberta elk. kk | |||
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Quote: I have been working the project for a long time. The gunsmith took his time with the recoil pad and the brake. Now it's time to finish off the loads. I agree about the bullet weight, and I have been working with some 180-gr Ballistic Tips. However, time has flown and now hunting season is near. And he wants to shoot with 250s. I'll be damned if a 180 gr. Ballistic Tip cruising along at 300 yards with over 3,000 ft. pounds of energy won't get an elk's attention, but who am I to argue? Personally, I shoot a .338 WM with 4831 and NP 250s. Seems enough gun for me. Oh, well, I'll just give him what he wants. Saturday I'm betting I'll find that sweet load that will give .66" groups at 100 yards. Then I can give him the target, give him the gun and cartridges and tell him the only thing standing between him and those groups is himself. I have told him he needs to shoot at least 100 rounds between now and his elk trip. kk | |||
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| one of us |
Hi, Kingfisher: Blind loading is on the agenda. So far, however, I have gone alone so I could concentrate on just getting the load right. I agree about the brake. I hate his. I had told him to install the Pachmyer and then see how he likes it, with the brake as a go-to idea. He has his own mind, however, and does not take instruction well. I'm supposed to meet him tomorrow at the range, and I'll have a couple empty cases in my pocket. kk | |||
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I'd like to hunt a Squirrel big enough for that kind of equipment. Do you hunt deer w/ RPGs? Reloader | |||
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| one of us |
KK, good luck to you guys. Unfortunately, big rifles aren't for everyone, and he may fall into that category. His testosterone may not be enough to overcome his flinch, but I hope that it is. I know I had that problem with my Accumark when I first got it, but that was mainly because of the damned brake. That thing was just plain ridiculous. In the overall scheme of things the recoil wasn't that bad. After I had it rebarreled without the brake it kicks about twice as bad, but you don't have near the muzzle blast. It took me a lot of shooting to get good with it, but I finally mastered it. I really feel for the guy. I wish you could convince him to switch to a lighter bullet. Maybe even a 210 gr. Barnes or something. That way he could practice and hunt with the same round, rather than practicing and hunting with those 250 gr. loads. Ugh. By the way, have you tried the blind loading trick? Where he turns away and you load the rifle for him? Every so often you leave the chamber empty. Maybe that will help him. I wish I was in Canada right now, I'd be heading to the range with you guys to get him lined out! | |||
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By John T: "However, by using slower powder you are not going to reduce the recoil, in fact quite the opposite. In all the recoil formulas the weight of the powder charge is factored in as the "ejecta" has a recoil effect." Even though the Physic Formulas say that recoil is dependant on the velocity of the projectile, it sure feels like a different kind of recoil. If you match velocities up equally w/ various different speeds of powder, the recoil feels noticably different. It seems a slower powder will lead to more of a push than a sharp punch like a fast powder. Good Luck! Reloader | |||
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