Full length resizing

[model14]

Do you full length resize your rimmed cartridges? If so, why, as opposed to just the bullet seating area? I always do, but I got to thinking the only reason I do is because that is what I was taught when I learned to reload (4 months, and 3000 rounds ago). I was recently reading the Hornady Reloading Manual and noticed that they recommend neck resizing only for rifle cases because it will give better case fit in the chamber and minimize case lengthening. No mention is made of straight walled cartridge cases. Fully resized cases in my 686 chambers have about .003 to .004" total side to side play. A non-resized case has about .001 to .002" play. By Hornady's reasoning that could lead to better accuracy because the bullet is better aligned with the barrel bore. Hmmmm?

 

[model14]

Do you full length resize your rimmed cartridges? If so, why, as opposed to just the bullet seating area? I always do, but I got to thinking the only reason I do is because that is what I was taught when I learned to reload (4 months, and 3000 rounds ago). I was recently reading the Hornady Reloading Manual and noticed that they recommend neck resizing only for rifle cases because it will give better case fit in the chamber and minimize case lengthening. No mention is made of straight walled cartridge cases. Fully resized cases in my 686 chambers have about .003 to .004" total side to side play. A non-resized case has about .001 to .002" play. By Hornady's reasoning that could lead to better accuracy because the bullet is better aligned with the barrel bore. Hmmmm?

 

[john traveler]

Full-length resizing of pistol and revolver brass is always preferable to partial resizing for the simple reason that you are likely to fire those cartridges in more than one handgun. Slip in the factor of magnum cartridge pressures, and neck sizing becomes a not-so-good idea because case expansion and contraction is now related to how many times fired, light or heavy load, etc. Semiauto pistols are completely dependent on perfect ammunition. Trying to chamber a slightly oversize case can not only loose you a match, but can cost you your life. Full length resizing is a small price to pay for full ammunition compatibility from one gun to another and for maximum reliability in one gun.

At one time, I played with partial case sizing for revolvers, and believe you me, it was frustrating to keep tossing the cartridges that would not chamber into the discard box for disassembly later. 100% full length resizing eliminated that problem.

Neck sizing only for straight-walled rifle cases is preferred by BPCR shooters that use one rifle for competition. It does give slightly better accuracy, and the relatively low pressures that BPCR cartridges operate at assure easy chambering. It does not assure compatibility between rifles of same caliber because even straight cases have some taper to them.

 

[model14]

John,
My question was strictly related to target shooting using the same revolver and, in fact, the same cylinder chamber. I have bore gaged all 6 chambers on my 686 and they are identical to at least a 1/2 thousandth. Now, on my older 4" 686, every chamber was significantly different and full length resizing was the only way to go. If you have seen my thread on 100 yard target accuracy shooting, you will see why I am looking for every advantage possible. My holy grail is the 1" group

 

[NKJ nut]

I full length resize my handgun rounds, because I want them to fit any of my guns. And I don't want iffy ignition. If the round doesn't fit well and part of the force of the firing pin strike is used up pushing the round forward slightly (seating the round) ignition would be compromised.

model14 given the use you describe, it probably wont hurt to give it a try. but don't expect an accuracy advantage from your revolver. The potential accuracy gain even in a very accurate rifle is very small. In a revolver at best there would be no difference.

 

[model14]

John, NKJ,
Thanks for the input.
You are probably right about the little gain in accuracy, if any. It was more of a learning question than my expecting much improvement in accuracy. However, I am at the point now where I "trickle" my powder loads and measure every cartridge for C.O.L. I will take any advantage I can get. I wish there was organized competition for bench rest handgun. It is a whole lot of fun.

 

[OU812]

Do you full length resize your rimmed cartridges? If so, why, as opposed to just the bullet seating area?

Yes I full length resize, I have done what you are going to do. Just added a few more steps.
1.Purchased new brass and weighted and placed in different bags per different weights all 50.1 in one bag 50.2 In next bag and so forth.
2. Picked out the bag with the most brass.
3. Sized and trimmed brass to the same over all length.
4. Loaded and fired this batch of brass(kept brass in its own bag did not want to mix with my reg brass)
5. Cleaned and neck sized case only enough to hold bullet.
6. Sized just top of case
7. To remove a possible problem did not crimp bullet, would load one at a time. later tried a slight crimp

Problems with doing this
No improvement over full length sized brass. (some groups were very good but others were just average.)
After 2 or three firings some of the brass was not loading into the chamber without some pressure. Sticky cases also during remove of said case.
Changed my plan a bit and started full length sizing on every third firing.
You can really try many different things during this testing. Different powders and weights using different primers including Benchrest. bullets size and weight etc etc etc. I used my chronograph and tried looking for a low standard of deviation in feet per second trying different powders and weights.
I was loading at the range to help cut down on time between loadings and shooting off a sandbag using a chair and heavy bench. Shooting from the 50 yard line and loading right on the bench.
After all was said and done either my firearm a Ruger in 45LC with a 7 1/2 barrel or some other factor caused no change in group size in the testing. went back to full length sizing threw all the brass in one tub and called it a day.

That was my shot at working with the components of reloading to improve the group size of a Ruger pistol. Did it help this firearm (NO). Will it help your firearm (maybe) you will have to give it a try and decide how far you are willing to go. The only thing I can tell you for sure is you will learn a lot during this search for the five shots under one inch, If you have a couple of weeks and live at your range or very close to it why not give it a go

 

[Hook686]

If the chamber will be the same, I see no problem with neck sizing. I neck sized 9mm when I only had a Wather P38 and had no problems. Add a S&W 3913 and then problems surfaced, as they did with a revolver, as there were 6 cylinder chambers the cartridge could be inserted into.

I switched to full length resizing and bought a Lee Classic Turret press. Previously I had been reloading using a Tong Tool.

 

[model14]

I am retired, have a lot of time on my hands, and I live 15 minutes from the range. Nuff said?

Again, thanks for the inputs, you guys keep me motivated.

OU812, I assume you trickle loaded the powder also? To me that should to be really important in this game. Maybe not. I have a L-N-L progressive, but I enjoy single cartridge loading and getting everything as accurate as possible within a group of bullets.

 

[OKFC05]

but I enjoy single cartridge loading and getting everything as accurate as possible within a group of bullets.

What you need is a single shot target rifle or handgun. That will keep you busy with all sorts of subtle techniques.

The techniques you are discussing are mostly irrelevant to revolver shooting under 100 yards range. At 50 yards, a 5% change in powder charge in a .357 only produces 1/16 inch change in impact, usually less than chamber to chamber variation, and far less than any shooter can achieve..

 

[Mr. Tree]

When I bought my 28-2 in 1968 I reloaded with a Lyman 310 tool and it does not full length resize. That's when I found out the revolver's chambers were not the same size. Some reloads would fit into a couple of chambers and not others. So I sent the gun back to S&W who redid the chambers. Although they are much better they still are not equal. Full length resizing is the only solution. With my rifles I do not full length resize (I can't with the 310 Tool)and always keep my brass isolated to each gun. If I pick up random 30-30 or 308 brass fired in someone else's guns some will fit my chambers others will not so I don't pick up brass.

 

[model14]

OKFCO5,
My current target load is 17.2 grains of VVN110 behind a 125 grain HP-XTP. My Chrony shows in the low 1400's for this load from my 6" 686.

According to my Vhita Vuori Loading Manual they get 1601 fps with 16.8 grains of N110 and 1772 fps with 18.4 grains of N110. Now 5% of 16.8 = .84 grains. This implies that an error (say upward) of 5% results in a load of 17.6 grains. Interpolating between 1601 fps and 1772 fps, 17.6 grains should result in a velocity increase to 1677 fps from 1601. How much change in bullet rise will occur at 100 yards (which is the distance I shoot) due to this charge error and velocity increase.? Using the Hornady online ballistics calculatoor I get the following results for a 125 grain HP-XTP zeroed at 25 yards and a sight height of 1.5" (my scope):

For 1601 fps, the drop is 1.9". For 1677 fps, the drop is 1.3". That is a change of almost 2/3", not 1/16". That is a huge error, when you are dealing with under 2" MOA's.
Based on this, you can possibly see why I "trickle" charge my loads for best accuracy. For 50 yard shooting, it will be less of an error, but still significant, when you are dealing with a 1" circle group.

Not sure where you came up with your information. Mine could be wrong. If you see an error, let me know.

I realize my own abilities, especially eyesight and steadiness will probably keep me from getting much better than a 2" MOA, but if I can eliminate all errors but mine and the revolver in my hand, I certainly have the best shot at that goal.

 

[OKFC05]

Not sure where you came up with your information. Mine could be wrong. If you see an error, let me know

Sure. Two problems.

First, my estimate was for 50 yd, not 100. Since the trajectory is a parabola (square function), twice the distance gives much more than twice the error.

Second, you are assuming that the dwell time of the bullet in the gun must be the same, or else the gun is rigidly fasten to a support. Neither is true.

With a hand-held gun, the dwell time is less for a hotter load, and the bullet comes out while the barrel is lower, somewhat offsetting the estimate from the tables that the bullet will land higher.

Like I said, if you get a long-range single shot, you can really get into some tricky precision stuff, without dealing with the fact that the 6 chambers of a revolver are never going to be exactly the same, and there is always some play in the lockup, however slight...

My friends with the 30 pound bench rifles even handload the exact same case for each shot to avoid case to case variance, and mark where the case "up" goes in the chamber!!! But they still measure their powder with a dipper or powder measure..

 

[OU812]

OU812, I assume you trickle loaded the powder also? To me that should to be really important in this game. Maybe not.

I did till I went to a Benchrest match and watched how they do it. They throw every charge into the case, I never did see a scale in the reloading area. And let me tell you them boys and girls can shoot. five shots in one hole under .250 after you subtract the size of the bullet was needed to win this thing and you had to do it 5 times that morning. then after lunch you get to shoot at 200yds. Those groups were also real good. The ones that I spoke to all said watch the flags the wind is what gets you. Get a good barrel tune it to shoot then watch your flags and figure out where the wind is going to push the bullet.

 

[ricks1]

you are not gaining anything in a pistol The neck sizing comes into play on a rifle " IF" you load for same rifle. The is no gap to jump in a rifle and no pressure loss. In a contender maybe but I would not think much difference.As was stated perfect cylinders on all are rare. Mag loads will show it up in that case. I had a Ruger that all 6 were different sizes. I did a little on that line that worked for a custom round. That was neck sizing 45 colt brass to 44 cal. Why? They will work in a 444 rifle

 

[riversalmon]

Had a 45 Hawk once, very consistent cylinder,however seating to bullet depth stabilized the rear portion of the case and allowed the front driving band on Keith swc's to enter the throats and forcing cone better aligned. Made a significant differance

 

[m657]

In my own experiments with 'precision' shooting, I found far more variance in group size came from what I did at the firing line, than what I did at the loading bench. YMMV.

 

[nicky4968]

With your straight wall case, your headspacing is (or should be) on the rim. You can trim your cases to all be the same length so that they will all crimp the same way. If you full-length size the case it will properly headspace on the rim. The repeatability of your load and crimp are far more important.
I understand serious .22 rimfire shooters check their rims with a special gauge and sort rounds by thickness. They can demonstrate that one lot of rounds will group around one area, and another lot of rounds will group around another area a few inches away. I frankly don't know if that applies to center-fire rounds (probably doesn't). Probably in that situation it isn't headspacing, but the priming compound gets ignited in the same fashion each time.