Sudden inaccuracy woes

[outdoorfan]

Boy oh boy! I was working on a high-velocity load for my .223, and things were progressing nicely. Typical groups at 100 yards were in the 1.5 range for 5 shots. I shot enough of them to know that the rifle was fairly consistently capable of doing that, and none of the groups were blown to 3+ inches.

I decided to shoot that load a couple more times to further evaluate, and low & behold, the groups exploded! In fact, they were so bad, I stopped after firing the first two shots for each load. I figured I must have had leading build-up, so I took the rifle back home and proceeded to clean, clean, clean.

After 3-4 times of brushing, patching, chore boy, then brushing again, I still couldn't get a patch to come out clean. It would always have some dark "greasy" type substance on it. So, I decided to brave it and use some 00 Steel wool on a brush heavily soaked with Kroil. I did two cycles of that, and the patch would still come out dirty. By then I figured that I had never cleaned a rifle that well before and I might as well go out and shoot it again.

So back to the range I went to finish off those groups that I started. Accuracy was no better!

I ordered up that 45 Frontier stuff (to get any possible leading out) that some on this forum have raved about. I'm thinking, could it be leading build-up? Maybe, but enough to change things so suddenly like what happened? I kind of doubt it. Could it be that I somehow damaged the rifling or the crown in the last cleaning before those groups went apart? Possibly.

I'm using an aluminum rod that is long, and at one point I was trying to shove a very tight patch through the bore. What happened was the rod got bent and ended up scraping the rifling as it passed through the bore. The aluminum was scratched up pretty good in one section of the rod, but I'm pretty sure that an aluminum rod has no chance of damaging the rifling.

I checked the crown the best I could, and it looks fine. Plus, I can't think of anything that I did that would have possibly compromised it.

So, here's the choices:

1. Leading that won't come out
2. Damaged crown
3. Damaged rifling
4. Other?

Anyone had this happen?

Wish I had a bore scope.

[cptinjeff]

5. Scope come loose?

[snake river marksman]

Is your scope loose or broken? Scope bases? Did something get lodged between the barrel and the stock? Have you been shooting some hard kicking monster and have developed a flinch?

[outdoorfan]

Oops, forgot to mention that the scope could be a culprit too, although it's a proven piece of glass (Sightron SII 4-16x42) that hasn't given me a lick of trouble over the years. All the bolts are tight.

No flinching!!! [smilie=s:

[stubshaft]

+1 on the scope going south.

[Shiloh]

5. Scope come loose?

+1

Had the same thing once. Gave me fits. Nothing was wrong, Clean barrel, proper loads, action screws tight. Finally the guy at the next bench suggested checking the scope.

Sure as heck,it was loose. Felt a little embarrassed. The other guy just chuckled and said it happened to him once also.


Check to see if the action screws are tight as well.

Shiloh

[outdoorfan]

Action screws are tight, scope rings are tight. I can't get at the base screws 'cause the tube is in the way, but I gave them a vigorous shake and nothing wiggled. I just mounted the scope a little while ago, so there's almost no chance the screws are loose. However, that leaves the scope itself as a potential culprit, so I'll pull it off and try another one next time I get a chance.

[Doc Highwall]

Just because the scope rings are tight does not mean that the scope is good. Try putting the rifle on a rest with a rear bag and while looking through the scope at something tap on the barrel or scope ring with a piece of wood and see if the image jumps around, maybe the internal spring broke that holds the inner tube against the adjustment knobs broke. If you have Weaver style rings you could also take the scope off and shake it to hear if something is rattling inside. A friend of mine had that happen last fall with his Encore in 12 gauge, gun was shooting great and with the next shot it was all over the place and you could hear that something was loose inside the scope.

[Greg in Malad]

I had the eyepiece lens in a Redfield 2x7 come loose once. Same thing happened, it went from shooting good to really bad in one shot.

[Larry Gibson]

What's the load?

What's the velocity?

What's the barrel's twist?

Larry Gibson

[44mag1]

does it shoot good with jacketed bullets? I had the same problem with my 222 with cast one time, first 15 round were great then all hell broke loose. I didnt have much trouble cleaning it and had no leading. my guess was heavy powder fouling and tiny cast boolits dont mix. I went back to jacketed in it and havent spent the time YET to figure out a good cast load.

[outdoorfan]

Good point on trying another load first. I'll probably do that before I pull the scope. That's an interesting observation.

Larry, this is a 1-14 twist. Boolit is the RCBS 55 grainer. Powder is Varget, and the velocities that I've been testing (and have been getting the best accuracy with this powder) have been from 2700-2850.

I think I might reduce down to 2400-2500 where I was getting okay accuracy (not as good as 2700-2800) and see if the groups come back or if they're still goin' nuts.

[prs]

The scope could be a factor, but outdoorfan also had a fouling problem and he never did get to "the bottom of". Get the barrel clean and consider subing the scope. But the velocity may have to drop or better lube or or or

prs

[405]

Doubt the scope would go south by shooting cast 223s! Could happen but seems strange. Scope mounts... maybe?
As far as the aluminum rod damaging the bore like that- not likely but my oh my get a good rod and bore guide! Since aluminum rods are soft, over time, they can pick up abrasives then the accumulated abrasives can harm the bore.

Still sounds like leading most likely culprit. Also, are the errant loads/bullets from the same batch that did so well or were they another batch, loaded later to duplicate the originals?

[outdoorfan]

Doubt the scope would go south by shooting cast 223s! Could happen but seems strange. Scope mounts... maybe?
As far as the aluminum rod damaging the bore like that- not likely but my oh my get a good rod and bore guide! I do use a bore guide, and this rod is supposed to be a good one (at least based on what I paid for it), but when it's that thin/long and you put a goodly amount of force on it, it can bend. This particular one regularly bends back by the handle, but in the one instance mentioned above that I really "put the screws to it" it bent further up the line. I then continued to run it up the bore. I shouldn't have, but I did. Since aluminum rods are soft, over time, they can pick up abrasives then the accumulated abrasives can harm the bore.

Still sounds like leading most likely culprit. Also, are the errant loads/bullets from the same batch that did so well or were they another batch, loaded later to duplicate the originals?

The errant loads were from another batch, but I'm very particular about the loading process/sequence, and I'm 100% sure I didn't accidently goof up some where.

[405]

OK, still pointing to something like leading. Since small cast bullets that are pushed to the limit at those high velocities and pressures are riding on the knife's edge of good-bad performance... any very, very small thing can throw a wrench in the gears. Nearly all bases have been covered so far in the posts so just have to explore each variable. The scope/mount thing is still possible and worth checking by putting on another scope. Lowering the velocity of the load and cleaning more often could be remedies... all just best guesses tho.

[CJR]

Outdoorfan,

I agree with all the comments on scope, mounts, rings and build-up of powder residue and lead. One other question. During the reloading of these cases, did you readjust your resizing die and push the case shoulder back too far and increase the headspace of the round with respect to the chamber?

Best regards,

CJR

[outdoorfan]

Nope. I use a Lee collet neck-sizer die, and the adjustment was consistent.

[StarMetal]

Although a scope coming loose is certainly a possibility I'm doubting it in this case mainly to the very low recoil of the cast load. Wise to check it though as you have. With you pushing the upper limit in velocity with case I'd almost bet on that it's fouling and especially after hearing what you're getting out of the bore. I doubt you hurt the rifling with an aluminum rod but you best be advised to purchase a better premium cleaning rod. Many like the coated rods I'm happy with plain steel. I hope that you are cleaning the bore from the breech end. As a shooter of HV with 6.5's I can tell you that you won't get as many shots through the barrel before fouling as you will with a lower velocity. Not to discourage you from shooting your accurate HV loads, but to clean more frequent between shootings.

[outdoorfan]

With you pushing the upper limit in velocity with case I'd almost bet on that it's fouling and especially after hearing what you're getting out of the bore.


I haven't done it yet, but I will first reduce the charge to see what happens. But I want to make sure that bore is clean first. I'm waiting on that stuff from Frontier 45 to come in. I'll try that. If it doesn't work and I still get dirst coming out, then I'll have to figure something else out.

[Larry Gibson]

Good point on trying another load first. I'll probably do that before I pull the scope. That's an interesting observation.

Larry, this is a 1-14 twist. Boolit is the RCBS 55 grainer. Powder is Varget, and the velocities that I've been testing (and have been getting the best accuracy with this powder) have been from 2700-2850.

I think I might reduce down to 2400-2500 where I was getting okay accuracy (not as good as 2700-2800) and see if the groups come back or if they're still goin' nuts.

Outdoorfan

My guess would be the powder is the cause. It is my experience that Varget burns efficiently only within a certain pressure span hich is usually at the high end. I have not gotten good accuracy with Varget using cast bullets unless top end loads were used. As you suggest, anothr load with another powder may be in order. I would suggest 4895, RL19 and AA4350.

Larry Gibson

[outdoorfan]

Outdoorfan

My guess would be the powder is the cause. It is my experience that Varget burns efficiently only within a certain pressure span hich is usually at the high end. I have not gotten good accuracy with Varget using cast bullets unless top end loads were used. As you suggest, anothr load with another powder may be in order. I would suggest 4895, RL19 and AA4350.

Larry Gibson

Thanks, Larry. I've got 4895, 748, & BLC2 in that general burn range.

I still don't understand why the good groups that I had, and than all of a sudden everything falls apart, if indeed it's the load that's the culprit. That's just weird. 6 or 7 good groups, and then nothing but mayhem!