223 bullet seating/accuracy issues

[capthook]

Hello All..

I recently purchased an Dillon xl650 press and have been reloading 223 ammunition with very mixed results. I have considered a number of factors including component quality and variability, bullet and powder selection, ect... But everything seems to check out except bullet seating and the resulting variability in OAL... For example, I have measured a sample (n = 20) from a batch of ammunition thats shot very inconsistently (0.3 MOA to 6 feet at 100 yards) and found that my OAL ranges from 2.321" to 2.334" - a spread of 0.013". The seating was done with RCBS and Dillon dies with similar results from both. Based on the foregoing I have three questions:

1. Is this OAL variability a potential cause of gross shooting accuracy errors (assuming all other factors are consistent and within specifications);
2. What is considered the maximum variability in seating depth and the resulting OAL when reloading for accuracy; and
3. What can I do to improve the seating depth problem?

Many thanks for your advice...

Best regards

Hook

[Big Buff]

I have not reloaded for some time and I am not as sharp as I use to be on the topic but a spread in your OAL of 0.013” or 0.3mm does not sound bad too me and I would suggest that this is not the cause of the inaccuracy, IMHO.

There might be a range of other factors coming into play here, give some more info on exactly what you are using, it might be that your gun does not like the particular load or bullet weight you are using.

[catnthehat]

What is your load, and bullet weight?
Also, are you measuring your OAL from the ogive or the tip of the bullet?
True OAL, the ONLY measurement you need to worry about BTW, is from the ogive to the eleade of the rifleing, that is where the accuracy matters.
How is your neck tension, are the case necks the same diameter after sizing?
These are just a few things to look at.
However, if you are having accuracy, it sounds like a neck tension issue or very bad bullet understablization - you arnen't using 75 grain Amax's perchanxce, are you?
Cat

[Bobby B.]

Hook,

First thing to clarify is what Cat already touched on, OAL measurement. If you are measuring OAL from headstamp to tip of bullet, the variation in OAL can be something as simple as the difference in the bullet tip if it is of lead.

Second, how does this rifle shoot with factory loadings? I've never seen a 6 ft. 100 yd group before.......except with a very tightly choked shotgun. If the factory loads shoot average sized groups but your handloads won't then we can analyze your handload components selectively.

Bobby B.

[catnthehat]

Originally Posted by Bobby B.

Second, how does this rifle shoot with factory loadings? I've never seen a 6 ft. 100 yd group before.......except with a very tightly choked shotgun. If the factory loads shoot average sized groups but your handloads won't then we can analyze your handload components selectively.

Bobby B.

Yup, definately something VERY wrong here, Bobby, and I am suspecting the very bad neck tension ( that will do it) , or too long a bullet for the twist, however, 6' IS a pretty large group!
Maybe something gone awry in the optics department?
You are right using factory ammo as a benchmark will likely go a long ways to solving this dlilemma...
Cat

[triggerpress]

If you are getting 6 foot groups at 100yds, the problem is not OAL variability. It's likely something much more serious. However, regarding your question of reducing OAL variability here's another variable....

The Dillon 650, by the nature of it's design has more spring in it than some other presses, particularly single stage presses. If, on the Dillon, you set you're OAL with only the bullet seating position "loaded" with a cartridge you will get one specific OAL. However, when you "load" all the other positions with cartridges, as you would in full production, the combined force of sizing, crimping, seating etc., will cause the OAL of your finished rounds to be slightly longer (because of a small amount of stretch in the press). The cure is to set your OAL with all the other positions on the shell plate loaded and exerting upward force on the die plate.

Once set up, the Dillon is capable of loading very good ammo, but you won't see benchrest shooters using them, so don't expect benchrest results.

For those not familiar with Dillon, nobody stands behind their presses better than Dillon. A couple of years ago I sent my 550 off to them. They rebuilt the entire thing, cleaned, lubed, replaced almost every part with an upgraded version, threw in some goodies and shipped it all back. No charge. Incredible service.

triggerpress

[Rusty P. Bucket]

I would be happy with a 6' group myself. I am in a major slump right now and can't hit the broad side of a barn with a handful of gravel. Sometimes it ain't the gun..

[capthook]

Hello all...

Many thanks for all your input - very useful...

By way of background, I am shooting a Savage 12 BVSS, chambered in 223 with a 26 inch barrel and a 1:9 twist. The load I am using was worked up on a friend's Dillon 550 press using 50 gr. Speer TNT bullets, Winchester brass that has been fired formed in the rifle, 25.5 gr. of H322 powder and CCI small rifle 450 primers. Target OAL (to the tip of the bullet) was 2.320". Based on the loads loaded on the 550, the rifle was consistently getting 1/2 to 1/4 inch 3 shoot groups at 100 yards under calm conditions. I can consistently reach out 300 to 400 yards on gophers and my best shoot on a gopher last season was lasered at 525 yards - so I know that the rifle/load combination works and I know that I can shoot the rifle. Having said that I am making the assumption that the problem relates to my making some as-of-yet unidentified error during the reloading process.

The problem started when I reloaded 200 rounds of 223 on my new 650 following the same specs previously used to reload on the 550. When I first shot the new loads, I shot four 3 shot groups on paper at 100 yards under calm conditions using a stable rifle rest and got all groups under 3/4 inch with a couple being ~ 1/3 inch groups. Satisfied, I then turned my attention to gophers. While many shots were obviously working, I started to get random shots that were grossly off target (ie up to 6 feet off). In one instance, a shot at a target ~ 200 yards downrange, the bullet hit the ground about 100 yards in front of me (where the ground was falling away)...

I assumed the problem was related to inconsistent powder charging by the 650 but when I got home and repeatedly tested the powder charge with the identical powder (ie H322) I got standard deviations ranging from 0.074 to 0.084 (n = 20, 5 trials)... I also weighed the remain loaded rounds from the "bad" lot and found that all where well within 174.2 +-0.5 grains - the theoretical optimum loaded cartridge weight. Based on this I have tentatively ruled out powder as the issue. Based on my past success with the rifle shooting this exact load, I have also tentatively ruled out shooter error and rifle malfunction as the cause of my problems (having said that I am open minded about these possibilties).

As mentioned, I am a beginner at reloading - this is my first crack (pardon the pun!!) at reloading (other than watching the process on the 550) so I assume nothing. I really have no idea what the problem is but I am leaning towards case preparation, improper sizing or bullet seating issues... Other than that.... who knows...

My immediate strategy is to load 10 rounds using hand measured powder charges and 10 rounds using 650 metered powder charges and shot these rounds with 10 rounds selected from the remainder of the bad batch to see if paying attention to powder matters makes a difference.

Any thoughts would be appreciated...

Hook

[Bobby B.]

Hook,

The reason why I suggested shooting some factory loads was to determine if the fault was not with the handloads but with the rifle, more specifically the scope. Every so often, a scope fails to maintain zero due to the retaining springs holding the reticle in place no longer perform their intended function (ie they break).

Bobby B.

[catnthehat]

Have you tried pulling some of the bullets to check the neck teension?
You can tell preety quick of your sizing die is not set properly that way, but I would shoot some factry ammo first, even cheap stuff.
With the TNT's, there is no possibility of TOO long a bullet and the load sounds right in the powder department also.
I am going to say either a scope problem OR ( and this is my no.1 idea) neck tension cause by improper sizing die set up, that will give you the wild groups you see......
Cat

[Bushrat]

How many of the rounds out of the bad lot went astray accuracy wise? Many or just a few? Of the remaining rounds how many were there left over. Noticed you said that one or some of the rounds were dropping way short of the target. Sometimes with progressive presses when your not weighing every powder charge and may not notice every powder dump to see that it is consistent, every so often the powder may bridge in the drop tube causing an incomplete powder charge in one case, and an overcharge in the next. A case with an undercharge would explain the shots that dropped way before the target and and the next powder drop will be an overcharge, that could explain other fliers and be causeing bullets to creep/spring back out the case neck if it is seated over a compressed charge of too much powder. It sounds to me from what you wrote that out of this batch you did not have a large number of these wild shots, only a few and that your test weighing of the remaining rounds may not have found any that had this problem and may all be within spec. Just food for thought and may not be related to your problem but does happen occasionally enough with progressive set ups that it is worth checking out.

[Unregistered user]

Don't rule out a bad batch of powder.

[capthook]

Hello all...

thanks again for all your insights and advice... great stuff...

I've worked (carefully) through the problem, purchased a Redding match grade sizing and seating die set, and have paid a lot of detail to Q&A while reloading. The problems have dramatically reduced but am still getting the occasional flyer or unusual misses... I found the problem yesterday while out shooting with a friend... Standing behind me while I shoot, he observed from time to time what appeared to be a vapor trail as my bullet flew down range... Curious, we set up a paper target at 100 yards and fired 4 5 shot groups, all under .6 inches. At the end, I had 1 shoot left so I fired at one bull that had no holes - the vapor trail was observed and when we inspected the targewt there was no hole... After 20 shots under 0.6 MOA therr was no way I missed the paopere... With that and the vapor trail we concluded the 50 gr Speer TNT was coming apart during the shot...

Has anyone heard about this happening with the TNT (at about 3400 FPS)... Any thoughts?

My plan is to drop the charge by 0.5 gr and see what happens...

Best to you all

Capthook

[catnthehat]

Methinks you are pushing the bullet too fast, whit a bore ( leade as well) that may be a bit rough.
Slow them down a bit a see what happens.
Too shoot upwards into the mid to upper 3,000FPS range, the 50 grain TNT in .223 is not the best bullet to use.
I would go to a Seirra Blitz King, Hornady Amax, etc., something intended to go faster!
If the bore and leade of the rifle are not mirror smooth, the lighter jacketed TNT's can be ripped and torn going down the barrel.
Couple this with speed outside of what they were designed for , and there ya go.
Cat

[capthook]

Thanks all...

I'm going to lap and polish the barrel, check the crown (although it looks good) and then if that doesn't solve the problem, slow the rounds down... I'll keep you posted...

Thanks for all your help...

Capthook