Trim length

[tcoz]

Using either the OCW or the ladder method, is it advisable to trim all test load cases to the same length? My cases are all once fired (in my rifle) Hornady, neck sized and length varies from 2.007 to 2.011. Should I trim all of them back to 2.007?

 

[hdwhit]

What cartidge are you loading?

Are you loading for a semi-automatic rifle or bolt gun?

Are you reloading for plinking or high precision?

 

[Slamfire]

I am of the opinion that trim length is primarily a safety issue, as you do not want the case neck to be pinched in the throat. See how much clearance I have?:




I don't shoot OCW, I load and shoot and see how the groups are going. It is possible that trim length has some effect on point of impact, but I am not good enough to tell. The real good shooters I know, they have the fundamentals of sight alignment and trigger pull down pat, they seem to be focused on wind reading as the wind will blow the shot feet and yards away from the center. Though some of my F class friends are going benchrest loading techniques. The half MOA target is a real challenge at 1000 yards.

Reload to your psychological level of happiness. If you think it makes a difference, it makes a difference, whether or not it actually makes a difference.

 

[Wreck-n-Crew]

Using either the OCW or the ladder method, is it advisable to trim all test load cases to the same length? My cases are all once fired (in my rifle) Hornady, neck sized and length varies from 2.007 to 2.011. Should I trim all of them back to 2.007?

Trim to the same length for consistency...so yes I would.

 

[30Cal]

It's not going to make a real difference, but you can trim them if you like.

 

[tcoz]

What cartidge are you loading?

Are you loading for a semi-automatic rifle or bolt gun?

Are you reloading for plinking or high precision?

I'm shooting .308 in a 20" Savage FCP-SR. Not plinking and not really high precision but I'm shooting for accuracy. Unfortunately, I'm currently limited to a 100 yard range so I'm thinking that maintaining a precise trim length won't be all that important. I'm hoping to eventually have access to a 300 yard range but even at that it may not matter.

I've used the OCW method in the past on a DDM4v11 AR and I liked the way I was able to arrive at a good accurate load with a minimum of test loads which is important to me since I live 45 minutes from the range and my shooting time is pretty limited. I didn't worry about precise case length in that case since I was dealing with a semiauto.

 

[Walkalong]

Trim them for safety, and square case mouths. I'm a big believer in square case mouths. Consistency is always good, and whether you trim to 2.000, 2.005, or 2.010 is unimportant, as long as that is short enough for your chamber (And they all should be).

I trim every time, then deburr and chamfer lightly. It doesn't take long. I used to only trim the long ones, but it just doesn't take much more work to trim them all. I doubt I could shoot the difference on target with cases from 2.000 to 2.010 vs all the same length, even if there is a difference.

Like Slamfire posted, there are far greater things to worry with. But I still like to trim.

 

[Bart B.]

I've not seen any accuracy difference in a .010" spread in OAL for cases head spacing on their shoulder. There'll be more spread in where the case mouth is in the chamber neck.

 

[joneb]

I like to make every thing the same, it makes finding and solving problems much easier.

 

[coloradokevin]

I'm in the trim every time crowd as well, though I'm not sure if it really matters or not. I shoot for precision, and to me the thing that causes precision (on the ammo side) is consistency in loading technique. But, how far you go with consistency is largely a matter of individual preference, and anal retentiveness.

My rifle loading process for precision and long range rifle work is:

1) Dry tumble (if very dirty -- skip if fairly clean)
2) Full length size and de-cap.
3) Trim, debur.
4) Wet tumble with stainless media (to clean primer pockets)
5) Prime
6) Charge with powder (weighing each charge)
7) Seat the bullet (no crimp)

Some people will read that and feel like I did too much (particularly on the issues of primer pocket cleaning, trimming, and weighing powder). Others will read that information and decide that I skipped a lot of steps (like neck turning, sorting bullets by weight, sorting brass by volume, bullet tipping and meplat trimming, annealing brass, etc). It all depends on your own desires.

Disclaimer: My shooting is done in field expedient positions using equipment I can carry with me in the field. I shoot mostly at steel targets, of various sizes, at distances ranging from 500-1,500 yards. Some of this I do competitively, some of it I do for work, and some of it I do for fun. A benchrest shooter will often be on the extreme end of the prep steps I mentioned above, while a tactical shooter will often be on the less extreme end of the spectrum.

 

[FROGO207]

You do not want to pinch a neck and raise pressure so trim if over max. I do not crimp my bullets in but if you do that it makes sense to trim every time to get a consistent crimp pressure. I feel crimping is not needed for my ammo to make it most accurate.

 

[hdwhit]

tcoz wrote:
I'm shooting .308 ... but I'm shooting for accuracy. ... currently limited to a 100 yard range...

I asked about the caliber because some cases need to be crimped and consistent case length is a part of getting a consistent crimp. Other cases headspace on the case mouth and for them case length can be a concern. As several others have already posted, with 308, it is less of a consideration.

Even though you may be constrained by a 100 yard range, the smaller the group you can get at 100 yards means you're on your way to smaller groups at 300. I am only interested in being accurate enough to consistently put a round in the circular indentation on the side of a milk jug at 200 yards (about the size of the vitals on the local deer and all the open spaces are about 200 yards) so I'm not the person to talk to about high precision shooting.

I do trim all of my bottleneck cases prior to loading them the first time. I know how much they lengthen on average on each firing and I know I lose about 40% of brass to the weeds, so statistically none of it is around long enough to need a second trimming.

 

[Bart B.]

Why are all my bottleneck cases a few thousandths shorter after firing?

 

[homatok]

Your cases are shorter after firing because they blow-out to fit the chamber of your firearm.
On trimming---As noted you must keep trim length shorter than chamber clearance to avoid pinching the case neck and raising pressure. If you really want to make your brass fit your chamber, you need to make and measure a chamber cast or impact duplication. You can then trim to whatever length the chamber clearance in YOUR firearm will allow (less a thousandth or three). If you do this, you will likely have to trim after each firing. If you are crimping, your brass needs to be very close to the same length or your crimping can (may) cause the case to bulge slightly at the body/shoulder junction, preventing it from chambering. Fluctuating brass length may have an impact on pressure and/or accuracy (maybe).