accuracy goes away when shooting sabots
 

Been shooting BP for decades, and sabots for probably 20 years now, but problems have happened with the last 3 rifles I've used.

I have tried a lot of substitute powders over the years, but usually use real BP.

First problem rifle was a Traditions inline. Great accuracy at first (I have never kept count of shots fired in a rifle, but usually shoot only about 40-50 rounds a year). After a couple years groups opened up so bad I couldn't keep shots on a target printed on 8½x11 paper anymore. I just set the gun aside as I had others I could use.

Then this past Saturday I got my CVA Wolf which has always shot well and is only a couple years old out to check for deer season and my groups have opened up to around 4-5" @ 100 yards????

I went home and got the old T/C Hawken with a GM LRH (1:28 twist) barrel out to check out so I could use it to deer hunt. This rifle has always shot under 3" groups at 100 yards with it's fiber optic sights. My first shot was 8" low-right, and the second shot was 5" left of the bull?????

I have always used water or window cleaner to clean the barrels, never had any rust in the bores, and take good care of my rifles.

It seems to me the most reasonable possibility is "plastic fouling" from the sabots. I never encountered this in the past, and had some rifles I shot a lot of sabots through (maybe 2-300 rounds over the time I owned them), but I find it hard to believe I've had 3 barrels (all by different makers) go bad in such a short period of time (number of shots through them).

I came home and ordered a bottle of cleaner (Shooter's Choice MC7) which is supposed to remove plastic fouling!

Does it sound reasonable/possible the plastic is my problem?

Like you said, it could be that you have a plastic buildup in your bore. You may want to scrub it good with that plastic solvent. That was my first thought as soon as I started reading your post.
Let us know how it turns out. BTW, what sabots were you using?

Been shooting inline guns since 1999, sometimes with large powder charges. Have never had any plastic fouling.

One other thing for inline rifles, I've burned out many breech plug flash holes, which has ALWAYS affected my accuracy. I've changed countless numbers of TC Encore platform breech plugs for that exact reason.
Its one of the reasons some guys are now installing vent liners in their BP's, to save the expense of new breech plugs. They just replace the vent liner.

I use Barnes Expanders in 250 grains and whatever sabots they come packed with (black sabot).

I have to agree with falcon. I've shot thousands of Barnes bullets and never suffered from any plastic buildup from sabots. However as I mentioned, burning out the flash hole (enlarging it) has always been an accuracy killer.
Shooting the Encore platform rifles, this I recognized and that was that each BP reacted differently. Some BP's lasted longer than others for some reason. However, when the groups started to suffer, replacing the BP brought the groups right back together again. A good thing to check. Assuming there's no scope, ring or mount issues.

Was the enlarging of the flash hole obvious, or would a small amount of erosion cause problems?

You can not tell it by looking at it, at least I couldn't. Of all the precision tooling I have, I'll admit I had nothing to check the size difference in the flash hole. A couple guys on the forum do measure them and maybe they'll respond.

I was shooting a tremendous amount when using Encore platform rifles each year. It NEVER failed that when my groups started to open up (consistently), the replacement of the BP ALWAYS brought the groups back together. Always. Note: Sometimes you just have a bad day. At times it may take only 100 rounds through one for it to start opening up groups, other times I might get away with 200 or 250 rounds. A local sporting goods shop kept a steady supply of BP's in stock, knowing I'd be right back.

Now I'm in no way saying this is your issue. Its just one possible contributing factor. I've seen guys start to have problems and sometimes it was the BP, other times it was his methods changed. Many times its mount, rings or a scope problem. I always suggest checking the mount, rings and scope. Muzzleloader can play heck on scopes and I certainly know about that myself. I learned that making sure that the scope tracked properly was very beneficial and saved me a lot of time and money.
Start with the basics, ensuring that you're using good propellant, that your mount and rings are torqued TO SPECIFICATIONS, with a torque wrench. (Caldwell makes a reasonable priced unit) Then I'd check the scope and make sure it tracks properly and that something's not wrong with the scope. Check the tracking by knowing exactly where your scope turrets are now. Dial up the elevation a full turn, then back to zero. Then dial it down a turn and back to zero. Do the same with right/left. If the scope is tracking properly and in good condition, you'll retain the same zero that you have prior to making the adjustments and your group, regardless of size, should go right back into place.

The typical reason would be an enlarged flame hole, stop at a weld supply place and get the set of wire use for clean the hole in a torch with that and a caliper or mike determine the size of the flame hole will likely be some disagreement about the max should be, I change mine at 37 Thousands.
You might consider a vent liner.
If that is no problem then check the mounting screws from stock to action

How old is the powder? Or worse yet, how old are the pellets? Last years propellants might be part of the problem and if they are still from the year before the might part goes away and becomes is.

IME: A burned out breech plug will ruin accuracy. One day earlier this year i fired 20 rounds of 120 grain charges through my Encore. Watched accuracy diminish with each shot.

I have a friend that was having trouble with his Encore grouping and was pretty darn upset. He was shooting the same charge and bullet he'd been shooting for years. I kept telling him to change the BP and his groups would most likely come back. Instead of paying attention, he kept fumbling with it and just goet more frustrated with a rifle he'd always relied on.
Mom (R.I.P.) always used to say, "You can lead a horse to water, but you can't make him drink."
After his constant threating to sell the rifle, send it to me and/or his constant B&M, this last early fall he finally took my advice and installed a new BP.
LOW AND BEHOLD....... his groups immediately tightened up to normal. Imagine that!

Its not always the case, but a lot of experience tells me when you're shooting tight groups, then the groups start getting larger, especially when using the same charge and bullet, the culprit "can" be an enlarged flash hole.

I went ahead and ordered a new breech plug. Since I'm shooting loose (Real ffg BP) powder with the "pellet" plug that came with the gun I figured that may not be the best combination for optimum accuracy anyway, so I ordered a BH209 plug for it.
The bore cleaner should be here tomorrow, but the breech plug won't be here until Dec 5. I'll probably wait until I have both items on hand to try a bench session to see if accuracy improves.

I have the BH209 BP in my CVA Wolf and have been using it for three years now. I wonder after reading this thread how much longer it will last. I dont shoot alot, just enough to make sure its dialed in. Right now the accuracy is phenomenal so if it starts to change I will keep this in mind. Thanks!

:) Seems that we're always spending money on our shooting passions. I've been putting off for years the purchase of a new hard rifle case. The one I've been using I've had since the late "70's". I finally got off my butt and ordered one on Black Friday from Midway. Just couldn't pass up the deal of $96 off.
Please report back on any improvements.

would you be willing to do each one separate though? Clean the barrel first and then shoot and see what happens to the accuracy and then install the new bp and shoot and test again? Just for curiosity?

These gages is an easy, and accurate way to measure flash hole size.


















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Maybe you just can't see it. It leaves only a very thin film in the corners of the rifling. And it adheres strongly to the bore. A bronze brush may or may not remove all of it. Even shotgun shooters use a plastic solvent to remove this film from their barrels.
It is a possibility but I now tend to agree with the other posters on the enlarged flame channel.

Shotgun shooters also have the ability of several shots fired rapidly from a hot barrel.

HUGE difference vs what a ML can do. Then you have the large difference in the temps the powder creates and how fast it creates it. When you really think about it, the comparison is badly flawed.

Modern sabots should not be leaving anything in a barrel unless you get it way too hot and blow a sabot. That is a load of hogwash that CVA still pushes to sell Powerbelts.
https://cva.com/wp-content/uploads/2...2Rev-12-13.pdf

I guess we are all entitled to our own opinion. You may be correct but I see no harm in using a plastic solvent occasionally even if just for my own satisfaction.

Well since i have SMLs using powders that FAR exceed BH209 in speed, pressure and temps, i think its safe to say sabot fouling is virtually nonexistent. Ive never seen any sabot fouling accumulate shooting loads well over 2600fps unless a sabot is blown.

Its pretty simple to see it. Poor boiling hot water down a bore. Run a patch....Sabot fouling will look like silly string snot on the patch. Solvents are almost worthless dissolving sabots. Bore creams/polishes work better. Brownwells shotgun wad solvent though gets very good reviews buts mostly just naptha (60-80%). Acetone has been suggested also but ive never tried it.

Tell you what...call both MMP and Harvester and ask them what will dissolve it. :p

I'll share my experience on suspected sabot buildup. I've fired thousands of rounds using sabots through a single rifle, to which there's never been a single shred of evidence that the sabot left residue of any kind in the barrel. The ONLY thing that affected the constant and consistent accuracy of the rifle itself, was the breech plug and flash hole enlarging.

History: Back in IIRC "97" when the Encore hit the market, I "thought" the same thing about sabots. When my groups started suffering, the first thing I thought about was "plastic". So what was the first thing I thought of to do, get the plastic out of the barrel. I won't go into the different processes I tried, but NOTHING I tried improved my groups, in fact they continued to get worse.
So I made the call to the most knowledgeable man in N.A. on Encore rifles. His first question was, "Have you replaced the BP?" Groups instantly went back to normal.

This isn't always the case with different rifles or shooters. Its just one major contributing factor long time shooters have recognized.

Just throwing this out as an additional bit of information...

IF he was shooting older sabots, those made before the current polymer high performance sabots - then there is a chance he does have plastic fouling in the bore that hides in behind the lands in the grooves....

Old polymers could certainly have problems. Its pretty obvious when you compare fired sabots such as the old Knight Brown or T/C Green to a more modern MMP Tan or Harvester light blue.

The new ones are a far better polymer and hold together MUCH better.

I got both the cleaner and the breech plug this week. Our deer season ends today (didn't want to shoot during season since our range in very close to some feeders & food plots), so hopefully I can get to the range soon and see if either change helps groups. I scrubbed the bore (didn't see any strips of plastic, but I did get a lot of black fouling and have been shooting black sabots ???). I plan to shoot one group with the old breech plug, then install the new breech plug and shoot another group.
I will post the results when I have the test completed!

Thanks to all who responded to the thread!

For a proper comparison test, make sure you clean it thoroughly before you shoot the new breech plug. You could have one of those rifles that don't shoot worth a damn till you have a good bit of fouling. From your latest post, it kind of sounds to me that you haven't been getting your rifle clean. That black stuff wasn't plastic fouling. Plastic fouling doesn't come off looking like you described. It comes out as little pieces and thin tendrils. What you pulled was carbon and soot. As sabotloader pointed out, the sabots of today are many times better than they used to be. Years ago I would end up with enough plastic in my rifling to mold a new sabot after around 30 shots. With todays higher end sabots from MMP and Harvester you won't be getting any plastic fouling unless your bore is ragged and needs some J-B run through it or you are really cooking it hard. Only one of my BP rifles will shoot sabots worth a damn so my experience with them is limited but I do know that you definitely don't shoot/load them on a hot barrel no matter how high end your sabots are.

Had a chance to shoot today, but conditions were not good (cold & very windy) so I just shot with the new breech plug installed and the bore had been cleaned with the cleaner I bought. Groups (at 100 yards) were reduced from slightly over 4" to around 2" today.
Plenty good enough to give me some confidence for the upcoming weekend gun season (Dec. 16-17).

When we get better weather I will try the old breech plug and see if groups open back up.

Barrel water baths are fine, even though I don't clean my bores in that manner. Just be sure none of the splashing water is getting under your front and rear sights, plus under the scope mount. If water got trapped there and the trapped water may not be clean water, rust might exist under those places.

I've seen it happen........

Well guys thanks for enlightening me on the new sabot composition. That will save me a step in my cleaning process. Now I don't have to use my plastic solvent, which I was skeptical about to begin with.
It just goes to show you that just because you're an old goat doesn't mean you can't learn anything new.

Try These #61 to #80 Drill bits, don't use the drill end, I always measure the flash hole when I install a Breech Plug. Then thru the year I occasionally check the hole diameter and replace when wear is a few thousands. Hope this helps
Just throwing this out, I shoot only sabots a lot of Black sabots, when I get done shooting I clean my barrel with hopp's Elite Cleaner and then heavily lube it with Slip 2000 (dissolves plastic). Then I do the 2 hour ride home. A few hours later normally I will clean My gun completely. I push a patch of hop's Elite thru the bore first, I always found a lot of black specs on the white patch and couldn't figure out what it was. This only occurred on the first patch thru, finally I decided that it was plastic from the black sabots. Best guess I could come up with.