crimp does affect accuracy!

[Axis II]

I worked up loads again for my 44mag carbine with IMR 4227, starline brass, cci LPP mag, and 240gr XTP. I will be letting a youth use this rifle in a few weeks so needed to find an accurate but low recoil load for her so I started at Hornady min and went to close to max just for my own knowledge. I I used to crimp these really good because I would have a lot of unburnt powder from the IMR 4227 in the barrel but I couldn't get better then a 2-3'' group with 3 shots. I lightened up the crimp on these loads and headed to the range and slightly over minimum charge I sent 2 through the same hole and the 3rd about 1/4'' away. I said yep that should kill a deer at 50-75yards and not kick her too bad. I have never got this gun to shoot anywhere close to that and I'm sure by lightening the crimp it helped.

anyone else noticed this?

 

[FROGO207]

By trial and error I have figured out that just enough crimp to keep the bullet from moving under recoil is fairly accurate AND prolongs the life of the case. I will usually use a faster burning propellant when I get any unburned left behind. Also with my experimenting with rifle ammo I personally get better accuracy with uncrimped bullets. Others have stated the opposite is true for them but I do not find that with my reloads. I only crimp for tubular magazine firearms and heavy recoiling revolvers presently.

 

[snakeye]

Hmmm....I have never crimped hard enough to affect accuracy, If I have to reset my crimp die I always slowly adjust until it passes a push test to prevent setback then pull the bullet and inspect it to make sure there is no excessive crimp.....

 

[Axis II]

By trial and error I have figured out that just enough crimp to keep the bullet from moving under recoil is fairly accurate AND prolongs the life of the case. I will usually use a faster burning propellant when I get any unburned left behind. Also with my experimenting with rifle ammo I personally get better accuracy with uncrimped bullets. Others have stated the opposite is true for them but I do not find that with my reloads. I only crimp for tubular magazine firearms and heavy recoiling revolvers presently.

even with a magnum strait walled cartridge? I know its a single shot so shouldn't have an issue, just making sure its okay for that caliber. Id like to try H110 with it but the 1gr spread freaks me out.

 

[Axis II]

Hmmm....I have never crimped hard enough to affect accuracy, If I have to reset my crimp die I always slowly adjust until it passes a push test to prevent setback then pull the bullet and inspect it to make sure there is no excessive crimp.....

I was doing it too much but was trying to keep from getting a barrel full or powder. this thing smokes like a muzzleloader and a lot of access powder. I read somewhere more crimp helps it burn.

 

[Havok7416]

I was doing it too much but was trying to keep from getting a barrel full or powder. this thing smokes like a muzzleloader and a lot of access powder. I read somewhere more crimp helps it burn.

A little crimp goes a long way quite frankly. You won't get "a barrel full of powder" no matter what you do unless you are referring to some leftover remains. Those are no big deal and matter not at all. I shoot some loads using Unique that leave powder flakes all over everything, but guess what? The bullet still hits what I'm aiming at and I still all away with all my parts attached after I'm done.

More crimp most certainly does not help anything burn. It may help slightly with pressure by holding the bullet back for a fraction of a second, but IMO it shouldn't be used primarily for that purpose. The real reason for crimp is to keep the bullets NOT being fired from jumping during the recoil of a fired round. Neck tension will take care of the bullet under normal circumstances and the primer will take take of any burning that is required.

 

[FROGO207]

H110 is the exception to the rule of 10% reduction of starting charges. Really, if you can hold the charge amount constant and pay attention there should be no problem. I just take a bit of special care when looking into the cases when I batch load and have had no problems in 30+ years of reloading for it. Also a rifle barrel will provide more protection in the event of a slight overload but I would not use this as a safety net for being sloppy with my charging techniques. The two things that help propellant burn better are slightly more crimp than normal and bumping up the actual charge. By slightly I mean a full roll crimp that does not deform the bullet any big amount in the cannalure area. If you still get poor results then a different propellant is needed IMHO.

 

[Jack B.]

I use pretty much the same load in my Henry 44 magnum. Starline brass , IMR 4227 powder ,CCI No. 350 primers or Winchester LP primers, Hornady 240gr. XTP or some 240gr JSP I get from Montana Gold Bullets. Give them a good roll crimp .I load 1 gr off of maximum per Hodgdon load data. IMR 4227 sometimes seems to leave powder residue but I have learned to ignore this as it is a very accurate load for me. Bullet and primer differences don't seem to matter.

 

[Virginia Jim]

I’m diggin’ your shooting bench design, Jack. I may have to copy that.

 

[Walkalong]

Some loads need a good crimp to burn well and get good start pressure. Crimp can indeed make a difference in how the powder burns and affect the ES & SD numbers. Accuracy may or may not be affected, just have to test it.

The two things that help propellant burn better are slightly more crimp than normal and bumping up the actual charge. By slightly I mean a full roll crimp that does not deform the bullet any big amount in the cannalure area. If you still get poor results then a different propellant is needed IMHO.

Agreed.

 

[Axis II]

View attachment 766770


I use pretty much the same load in my Henry 44 magnum. Starline brass , IMR 4227 powder ,CCI No. 350 primers or Winchester LP primers, Hornady 240gr. XTP or some 240gr JSP I get from Montana Gold Bullets. Give them a good roll crimp .I load 1 gr off of maximum per Hodgdon load data. IMR 4227 sometimes seems to leave powder residue but I have learned to ignore this as it is a very accurate load for me. Bullet and primer differences don't seem to matter.

I lost my notes that had the good full power load. I'm working on a light recoiling but accurate load for a 10yo girl to use for youth gun season. once I find a good load she can handle I'm going to move higher for myself. I was just surprised even with a start load the less crimp allowed it to shoot pretty well.

 

[Jack B.]

I’m diggin’ your shooting bench design, Jack. I may have to copy that.

Sorry I can't take credit for the bench design The members of the Titusville Rifle and Pistol Club built these before I became a member. They are pretty comfortable to use when shooting from the bench. The tops are screwed on ,makes changing the top easy. Which we do when they get worn.

 

[Jack B.]

I lost my notes that had the good full power load. I'm working on a light recoiling but accurate load for a 10yo girl to use for youth gun season. once I find a good load she can handle I'm going to move higher for myself. I was just surprised even with a start load the less crimp allowed it to shoot pretty well.

If your gun will shoot 44 Specials, just load some of them. There's hardly any recoil with even hot 44 Special loads.

 

[Walkalong]

I used to shoot .44 Specials out of my 94 all the time. Lots of low recoil fun.

 

[Axis II]

If your gun will shoot 44 Specials, just load some of them. There's hardly any recoil with even hot 44 Special loads.

I'm not sure if it will, Its an H&R handi rifle. Her dad said she shot a box of 22-250 by herself off bags so I'm sure she can handle the 44mag. going to let her dad shoot it first to see if he thinks its too much for her.

 

[FROGO207]

It should shoot the specials just fine. I have one in 500 S&W and there is no big difference in accuracy between the specials or the mag loadings other than point of impact in mine. Yeah if she shoots a 22-250 then she should be good with 44 MAG IMHO. I would just go with a just under standard to standard crimp with a Handi Rifle if it were me.

 

[buck460XVR]

I lost my notes that had the good full power load. I'm working on a light recoiling but accurate load for a 10yo girl to use for youth gun season. once I find a good load she can handle I'm going to move higher for myself. I was just surprised even with a start load the less crimp allowed it to shoot pretty well.

IMR4227, while a great accurate powder for .44 mag, is very dirty when downloaded(as you have found out). A heavy crimp is not going to help much in this scenario. For reduced loads, you'd be better off using a faster powder than IMR4227(virtually all handgun powders are faster than IMR4227). Still, if it's accurate, and you don't mind the smoke and unburnt powder, go for it. Still from my experience IMR4227 is an expensive powder per ounce and it takes a good charge of it, even for reduced loads. If IMR4227 is all you have, I understand, but would recommend you try Unique if you are looking for a reduced .44 mag load as compared to IMR4227.

 

[Axis II]

IMR4227, while a great accurate powder for .44 mag, is very dirty when downloaded(as you have found out). A heavy crimp is not going to help much in this scenario. For reduced loads, you'd be better off using a faster powder than IMR4227(virtually all handgun powders are faster than IMR4227). Still, if it's accurate, and you don't mind the smoke and unburnt powder, go for it. Still from my experience IMR4227 is an expensive powder per ounce and it takes a good charge of it, even for reduced loads. If IMR4227 is all you have, I understand, but would recommend you try Unique if you are looking for a reduced .44 mag load as compared to IMR4227.

yep, all I have as of now. Gander went under so I got it and benchmark for like $20-lbs. once its gone I'm switching.

 

[RecoilRob]

At reduced velocity you might consider WW231 as it meters very nicely and burns clean. You cannot develop maximum velocities with it, but over 1100fps with a 240 is doable and it'll be economical to boot. Just be VERY careful about not double-charging a case as the 44 Mag can hold a lot of powder and the max charge of 231 won't fill it half way.

 

[JohnhenrySTL]

I don’t normally crimp much but for .357 I find it’s the only way for consistent velocity. I have tried only 4227, and H 110, both went from being over 150 FPS different, to within my usual 30 FPS.

 

[buck460XVR]

I don’t normally crimp much but for .357 I find it’s the only way for consistent velocity. I have tried only 4227, and H 110, both went from being over 150 FPS different, to within my usual 30 FPS.

What I have found with both H110/W296 and IMR4227 is the consistency of the crimp matters as much as how heavy the crimp. This is both with accuracy and low SD. This can only be obtained with consistent case length. If you have cases that vary in length, so will the amount of crimp.

 

[WelshShooter]

My Gallery .357 Magnum loads fired from a Marlin 1894C
5.6gr Ramshot True Blue
158gr Lead Truncated Cone
Starline Brass
CCI Small Pistol Primer
COAL = 1.600"

I apply a small taper crimp around the canelure of the bullet. Recoil is minimal and groups well (read: fist sized group) at 25m offhand. I fired these last night using new Starline brass. In the past I have found the grouping to be a bit sporadic. I do know that a good crimp is only as good as consistent case length, so maybe my previously used brass is a different length to my Starline brass, thus not giving a consistent crimp?

Anyway, I digress. Crimping may not contribute to improving accuracy, but a poor crimp can surely be a detriment to accuracy.

 

[41 Mag]

Years ago I was shooting in the neighborhood of around 2-300 rounds a week out of 357, 41, and 44 combined. The powder I used was 296. At that time it and H110 both were different colors and textures as well as had varied listed loads.

I found that crimp made a dramatic difference in groups that I got with all three calibers. A lot of the rounds were only at 25yds due to being at a close indoor range, but when I could get to the longer outdoor ranges or up to our farm I stretched things out to 50, 75, and 100yds. The 44 had a 4x scope mounted on it and from a bench rest I shot plenty of 2" and sometimes less groups at 100yds. The others had fine target sights and I could usually keep 6 rounds close to or under 6" at that range.

When I was preparing for a handgun hunt up in Wisconsin I was fiddling with loads and couldn't get these same revolvers to group under 6" at 50yds using the same loads. After fiddling with everything else I managed to root up a few rounds of my previously loaded ammo. It only took a quick look at them to notice the difference in crimps. After backing the crimps off on the new loads things went right back to the old ragged hile groups I had once been getting.

Later on I suggested my 41 load to a good friend. He called me on the next weekend blabbering about how bad these were shooting and couldn't get anything to group wpr5h a farm. I advised him to only use enough crimp to roll the lip of the case into the bottom edge of the cannalure. He still was having issues so i dropped by his place to see if i could help. First thing was all of his brass was a different lenght. I trim all of my revolver brass afyer 2-3 firings. We trimmed all of his to the same length and then started seating and setting his crimp. Once we had things set we loaded 20 rounds to see what happened. I first loaded 6 of the rounds he had previously loaded and fired them off hand at 40yds. Then I loaded 6 of the newly loaded rounds and fired them as well. We had a fairly stiff wind but I still managed to hold things together enough to show the differences.

The left side group were his original loads and the right side were those we trimmed and backed the crimps off on.

The thing I feel happens is that there is SO much data out that says when using these type powders that you must use a heavy crimp. Well if you sizing die is proper the case neck tension should do about 90% of the holding, and the crimp should take care of just holding the bullet in place. Ive seen loads where it looked like the lip of the case was almose swagged into the jacket. Then ive also aeen just the opposite where there was hardly a noticeable roll on the lip at all. Both of these could have been the result of improper trims ir none at all. For consistency the cases at least should be within about. 002" or .003" at the most.