7mm STW Brotherhood - For those who shoot the 7mm Shooting Times Westerner

[7stw]

View attachment 13081

Thanks guys. The only reason I started there was the gunsmith I've been working with recommeded it as a starting point as he shoots 84.5 RL22 in his stw and has for 20+ years? I will take heed and start load development on a milder one asap. I've worked too hard to get her to this point to start backing up now.

The target above was from this evening, I caught a cool rainy spell and sent 4 down her then cleaned again, just continuing the breakin process. That group measured .345" my best yet, maybe because of the cool eve we had today? Anyway I'm well pleased and thanks for the input, hopefully the cooler loads will group as good or better.

Monz, I don't mean to sound as if I know everything about everything, but there is no doubt in my mind, and I don't even care what the " gunsmith " said, even at 83 grains, you are WAy over 65,000 psi, even at cooler temps. RL22 is very tempermental, and if you get a warm day, your pressures will skyrocket, and you will need a hammer to get the bolt open. That ain't no theory, that is a fact. You probably can use 83 grains of RL25, but not 22. Been there, done that. Again, don't take it the wrong way, but the fact is, you have three " seasoned " STW shooters here advising you to back off, and one guy near you telling you that you are ok. Additionally, you have a new barrel, and your friends barrel may have a few more rounds through it, which means that his throat may be receding, and that MIGHT allow him to shoot more powder. But make no mistake about it, I will guarantee you that if you put a piezo pressure monitor on your barrel, you will be near or in excess of 70,000 psi. ( on a cool day). Add a little heat, hello 75,000.
Back down the nitro, save face, save barrel, still kill deer.
P/S, I too have 20 + years experience with this cartridge. gun)
Again, NO HARM INTENDED!!!!!!

 

[7stw]

After a really good start (under an inch at 250 yards), the new build has started to string hard horizontal Then it will randomly go vertical......or well, random. I've changed just about everything including action torque, rings, mounts, load length, charges, bullets, seating depth...and even bedded it again. I've never had a rifle give me such a fit. Others have shot it with similar results.

Tonight I decided to load into the lands. Barrel has less than 200 rounds on her.

What do you make of this?

All 5 lands on the 5R barrel show this pattern.

Lycan,
I don't know any of the variables, such as how many shots in the groups, barrel contour, action make, temperature when fired, but TYPICALLY, vertical stringing is normally ignition related, or lack of. Horizontal is USUALLY , bedding, scope bases, scope, etc.
From what I read, it seems like you have change or altered everything except the scope, and that very well may be your culprit. However, I don't like that scratching or engraving on the bullets either. How does the barrel clean, is it slick and smooth, or are there roller coaster high spots?
That scratching still puzzles me. It almost looks like machine or tooling marks, left when it was chambered. ( just a thought). But you did say that it shot good at first!
Maybe try swapping scopes, and if no change, have it looked at by a GOOD smith' and have him put a bore scope in it and check it from breach to muzzle.
It is possible that you have built up carbon in the throat. That would scratch the bullets, and wreak havoc on accuracy. Carbon and primer residue compress, liquify, and freeze up in new throats quite often. Those are the top picks that come to mind. It's a place to start!!!

 

[ButterBean]

Lycan,
I don't know any of the variables, such as how many shots in the groups, barrel contour, action make, temperature when fired, but TYPICALLY, vertical stringing is normally ignition related, or lack of. Horizontal is USUALLY , bedding, scope bases, scope, etc.
From what I read, it seems like you have change or altered everything except the scope, and that very well may be your culprit. However, I don't like that scratching or engraving on the bullets either. How does the barrel clean, is it slick and smooth, or are there roller coaster high spots?
That scratching still puzzles me. It almost looks like machine or tooling marks, left when it was chambered. ( just a thought). But you did say that it shot good at first!
Maybe try swapping scopes, and if no change, have it looked at by a GOOD smith' and have him put a bore scope in it and check it from breach to muzzle.
It is possible that you have built up carbon in the throat. That would scratch the bullets, and wreak havoc on accuracy. Carbon and primer residue compress, liquify, and freeze up in new throats quite often. Those are the top picks that come to mind. It's a place to start!!!

7 it looks to me like its going way to far into the lands .......Throat Erosion?

 

[Lycan]

7 it looks to me like its going way to far into the lands .......Throat Erosion?

At under 200 rounds? I hope not.

I was trying to get an idea of how far it was to the lands (I know smoking bullets isn't a precise measurement). Typically, I find the bullets hit the lands and stop rather abruptly. You get a touch with each land and if you push much harder, you'll stick the bullet.

In this case, it looks like the leade has a shallow angle and the bullet wipes easily until the front of the round hits the apex where the full land height begins. At least that's one of my theories. I just never had one do that before. She'll chamber an Accubond at 3.90 COAL.

Barrel countour is Remington Varmint in stainless. Not light. The action is the controlled feed Winchester Classic long action. I've ran it with and without the center screw.

She's not went over 22 rounds between cleaning. Cut-rifled Obermeyer tube so it has the tight lands....which perplexes me even more.

Scope is a brand new SIII, but I did have to send it back as it came with a loose dress ring in front.

Stock is a McMillan A5 with pillars.....that went back once due to having the cheekpiece hardware relief cut off axis.

This has not been an easy project.

 

[Lefty7mmstw]

Lycan, I lost a 7mm ultra at 600 rounds, so barrel wear isn't out of the question if she has gotten hot and was made to shoot anyway. I got 1500 rounds on my sendero though and the throat would still stop a bullet cold, so me thinks you have a tapered throat causing issues once it's a bit worn or some carbon buildup in the lead/origin.

What do you use for cleaning solvent??? If you aren't using a powder only solvent and a brush at least every few cleanings, you'll eventually get some nasty carbon in the lead area that will require a lot of patience to get out. I went to a combo cleaner and **** near killed three good rifles because of this.They were all overbore and all had baked in carbon and the groups went to pot. A soak and clean regimin cleaned my stw and my 300 win rather quickly, but my 7 rum took a lot of work and a couple of thousand brush passes before it came out of it.

 

[Lycan]

Lycan, I lost a 7mm ultra at 600 rounds, so barrel wear isn't out of the question if she has gotten hot and was made to shoot anyway. I got 1500 rounds on my sendero though and the throat would still stop a bullet cold, so me thinks you have a tapered throat causing issues once it's a bit worn or some carbon buildup in the lead/origin.

What do you use for cleaning solvent??? If you aren't using a powder only solvent and a brush at least every few cleanings, you'll eventually get some nasty carbon in the lead area that will require a lot of patience to get out. I went to a combo cleaner and **** near killed three good rifles because of this.They were all overbore and all had baked in carbon and the groups went to pot. A soak and clean regimin cleaned my stw and my 300 win rather quickly, but my 7 rum took a lot of work and a couple of thousand brush passes before it came out of it.

She's never been allowed to get hot (never more than three rounds before a complete cool down) and never went over 20 rounds without cleaning. I've been using CR-10. Wet patches and maybe 5-6 strokes with the brush seem to get her clean in a relatively short amount of time. That stuff works fast and I don't let it sit in the barrel long before I wipe it dry. Patches are white in 10 minutes.

 

[Lefty7mmstw]

She's never been allowed to get hot (never more than three rounds before a complete cool down) and never went over 20 rounds without cleaning. I've been using CR-10. Wet patches and maybe 5-6 strokes with the brush seem to get her clean in a relatively short amount of time. That stuff works fast and I don't let it sit in the barrel long before I wipe it dry. Patches are white in 10 minutes.

I know I went to combo cleaner ( I forget which one but not Barnes) and to shooters choice copper instead of using hoppes #9 also like I'd done for years and I literally filled the origin of the rifling in one rifle and had significant deposits in another two rifles in a couple hundred rounds per each. It took a LOT of brushing with a powder only solvent and some serious soaking to break the deposits. Kroil, shooters choice, hoppes #9, and hoppes elite gel are all on my cleaning bench now and I go until I have visual confirmation as clean patches lie; they only tell you your solvent can't get anymore, not that the bore is clean. I also have JB bore paste for tough jobs.
Barnes has a good rep. for cleaning a bore, but most cleaners will take on a 308 or '06 and do well with them. It's the overbore rifles some cleaners have trouble with, because the carbon bakes in so badly.

It could partly also be the rifle breaking in. I've seen some rifles not like a load as well after some time is on the barrel, but accuracy usually doesn't fully go to pot either. How many different bullets have you tried- some barrels have an affinity for one brand or another and they will tell you pretty bluntly what they want.
I've got to get my 7stw to the range to chase a few more deamons this week myself. I bought it this spring trading in my sendero 7stw and have been chasing deamons all summer with it. First it was the scope rings, stock wacking the barrel, trigger to stiff, etc. Now the trigger guard screws have been backing up so they were replaced with hex- head for more bite. The last gruop I fired with the sendero was still under .4" at 100 yds.; I probably shouldn't have traded it.

 

[7stw]

Lycan, I got to thinking about your ploy today, and I do think that what your problem is , is in the throat, as I had hinted about last nite. You said that you have shot a few different bullet types, and the bullets in the pix are CT bullets. If you are not THOUROUGHLY cleaning it before going to another type of bullet, what is happening is you are effectively " laminating" the lead edge of the throat, and then what happens is the chamber pressure jumps around. That will in turn throw accuracy, ( spelled consistency) , right out the window.
I know you are battling with a few things that just aren't right, such as the stock, scope, etc., but that marking on the ogive of the bullet aint caused by any of that stuff.
Just a little reminder, you do NOT have to seat the bullet into the riflings to get good accuracy. NONE of mine are into the throat, all fit into the box, ( Winchester, and Remingtons), and they all shoot below MOA.
I would just take a few steps backward, get back to basics, clean barrel, target reading, and load progression, without making too many changes at once. The gun dosen't have that many rounds through it, so the problem and cure has to be something simple, and probably overlooked. These rifles will foul a throat in a nano second, so that must be considered. Twenty rounds may be to long of a interval before cleaning. Try ten or twelve, and see what happens, but you have to get it " mint " clean first, then go from there.
Try scalding hot water , poured down the barrel. This opens the pores, and releases a lot of the carbon and copper, and moly too. It works great, and you will be amazed at what comes out of the barrel, on your jag patch, especially if you use JB or similar compounds. Good luck my friend.

 

[Lycan]

Those aren't CT's....those are Accubonds painted with a Sharpie just so I could see where the lands were. I've already shot out a 7 STW barrel before this one at about 1500 rounds, but never had this trouble. I've also never had a gun where I could push a bullet up the lands. When they hit the lands, they typically stop rather abruptly. In the picture, you can see the wipe marks and those only occur in line with all 5 lands. Anyone else ever see this?

In this barrel I've run 160 Accuonds, 168 Berger VLD's, 162 SST's, 162 A-max, 150 Ballistic Tips (to check the velocity against my old barrel) and 154 Hornady Spire points (I had laying around).

I do think it's in the throat and I'm going to chamber cast and have my smith scope it out. It wouldn't however, hurt to scrub her out with some hot water so I'll be happy to take that advice.

Thanks!

 

[7stw]

Those aren't CT's....those are Accubonds painted with a Sharpie just so I could see where the lands were. I've already shot out a 7 STW barrel before this one at about 1500 rounds, but never had this trouble. I've also never had a gun where I could push a bullet up the lands. When they hit the lands, they typically stop rather abruptly. In the picture, you can see the wipe marks and those only occur in line with all 5 lands. Anyone else ever see this?

In this barrel I've run 160 Accuonds, 168 Berger VLD's, 162 SST's, 162 A-max, 150 Ballistic Tips (to check the velocity against my old barrel) and 154 Hornady Spire points (I had laying around).

I do think it's in the throat and I'm going to chamber cast and have my smith scope it out. It wouldn't however, hurt to scrub her out with some hot water so I'll be happy to take that advice.

Thanks!

Lycan, yeah, I do really believe that you have a throat issue, whether it be build up, or damage, or whatever. I don't know what your OAL is, but typically, it is difficult to get the touch the throat, without being awfully long. The picture dosen't look as though it is to much longer than Remington box length which is about 3.700+-. Normally the free bore is about .250, and as much as .375 in the STW's, and I have seen as much as .400 in some other calibers.
The chamber cast is a great idea, but I wonder if it would be a good idea to do one before you scour the barrel, and one after, for a comparison. ( just a thought).
I hope that things work out for you, and that you find the problem. I really feel like it is a build up issue, and that's simple to remedy. The chamber cast idea is a really good idea. That will reveal a lot of info.

 

[browtinehunter]

HEY;


I see a lot of people have 26 to 28 inch barrels in 7mm stwlightbulb
And few of you have 24 inch barrels, what Velocities
are you getting out of the 24 vs 26 inch barrelsgun)

Tom

 

[ButterBean]

HEY;


I see a lot of people have 26 to 28 inch barrels in 7mm stwlightbulb
And few of you have 24 inch barrels, what Velocities
are you getting out of the 24 vs 26 inch barrelsgun)

Tom

Minus 100 to 150Fps on the 24"vs 26"

 

[ButterBean]

Lycan, yeah, I do really believe that you have a throat issue, whether it be build up, or damage, or whatever. I don't know what your OAL is, but typically, it is difficult to get the touch the throat, without being awfully long. The picture dosen't look as though it is to much longer than Remington box length which is about 3.700+-. Normally the free bore is about .250, and as much as .375 in the STW's, and I have seen as much as .400 in some other calibers.
The chamber cast is a great idea, but I wonder if it would be a good idea to do one before you scour the barrel, and one after, for a comparison. ( just a thought).
I hope that things work out for you, and that you find the problem. I really feel like it is a build up issue, and that's simple to remedy. The chamber cast idea is a really good idea. That will reveal a lot of info.

Hey 7 look close at that pic again those are land markings.....it has me confused a bit

 

[Lefty7mmstw]

Minus 100 to 150Fps on the 24"vs 26"

about 50fps south of my dad's 25" bdm with brake with my 24" lh bdl, and his was as fast as my sendero with a 26" pipe. A lot of it is the load. I've seen the loss change with different powder and/ or bullet weight.