I think I found the culprit of having a bolt that was tight pulling back. I measured the spent brass and they were anywhere from 2.871 to 2.883 long. The specks I found for my 7MMSTW is 2.850 overall length.

I am going to shoot a 10 shot ladder test with 140 grn Accubond bullets this weekend with IMR 7828 and H-1000 to see what they will do in my gun. I am also going to shoot a 5 shot ladder of H-1000 with 150grn SMK to see what the difference is to the IMR 7828 that I already ran.

Also to test this weekend will be a 5 shot group of H1000 under 168 grn SMK to see what the potential is for this combo.

I am going to try to shoot a box test of 150grn SMK over 78.5 grn of IMR 7828 to see how my Millet 6X25X56 AO varmint scope will track. It has been holding zero very well so far during my load testing and during my first hog hunt so far.

Hey Harold,

My 7mm STW likes 79.0 grs. of IMR-7828 with the 140 gr. AccuBonds. It shoots .616 out of my rifle. 76.0 grs. of RL-22 shoots even better for me with the 140's. I just took a Texas pronghorn at 292 yards last weekend with the STW.

Good Luck!!

Bob

Nice goat BOB.

I was a little concerned that the 140 grn bullets would be a little light for this large of case. It has a 1:9.5 twist.

I have been shooting 78.5 and 79,5 grn of IMR 7828 with 150 grn SMK and they shoot 3/4" to 1" groups at 200 yards. The 79.5 grn load was giving me pressure signs when the temperature got above the mid 80's. I am going to see if I can push a 100grn bullet close to the 4K range and see what happens on a pig? I need to research what bullet that will be.

quote:

I was a little concerned that the 140 grn bullets would be a little light for this large of case. It has a 1:9.5 twist

My STW is a 26" laredo. I don't know the twist off hand. My cases are necked down 8mmmags. I have two loads one in 140accubond and the other 120BT. The 140s are 3400+ using 7828 and the 120s 3600+ using RL22. Exactly same weight load in both. Those loads are several grs over the Nosler max so I won't post them. My point of impact at 100 yds is about .75" apart and both are sub.75moa. The 140s have taken several West Texas deer a long range the 120s will destory a jack rabbit or coyote.

Well my sticky bolt problem is back. The symptom is an easy bolt lift, but I have to take a hammer or something similar to tap on the bolt to eject the shell. You can insert the shell back into the gun and it will chamber with no problem, but still have to tap the bolt back to eject the case? This does not happen on all rounds but most. Do I need to polish the chamber and neck area?

My ladder test of IMR 7828 with a 140 grn Accubond bullet, case trimmed to 2.834 with CCI magnum primers. At two hundred yards temperature varied from upper 80's to mid 90's with intermittent winds from right to left at about 7-10 MPH. Most of the day was sunny and hot with little wind. The wind would pick up as passing showers to the east (right of me) went by.

1. 79 grn 2882 FPS sticky bolt
2. 79.5 grn 3425 FPS sticky bolt
3. 80 grn 3427 FPS sticky bolt
4. 80.5 grn 3444 FPS no sticky bolt
5. 81 grn 3468 FPS sticky bolt
6. 81.5 grn 3499 FPS sticky bolt
7. 82 grn 3510 FPS no sticky bolt
8. 82.5 grn 3545 FPS sticky bolt
9. 83 grn 3562 FPS sticky bolt
10. 83.5 grn 3614 FPS no sticky bolt

6,8 and 10 grouped in about a 1" group high and to the right
3,4,5,7,9 grouped in about a 1 1/4" group low and to the right

1 was 2 1/4" low and 2 was center 2" right

All measurements of the cases are within SAUM specs after firing.

On the H-1000 with 150grn SMK

80 grn 3241 no sticky bolt same zero of 150 SMK and IMR7828 78.5 grn
80.5 grn 3270 no sticky bolt
81 grn 3302 no sticky bolt same zero of 150 SMK and IMR7828 78.5 grn
81.5 grn 3316 sticky bolt
82 grn 3488 sticky bolt

H-1000 with 168grn SMK

75 grn 2935 no sticky bolt
75.5 grn 2965 no sticky bolt
76 grn 2985 no sticky bolt
76.5 grn 2988 crushed at shoulder and split case about 3/8" from head
77 grn 2999 split case about 3/8" from head

I checked my velocity of the IMR 7828 of 78.5 and 150 grn SMK at 3310 and they typically had a sticky bolt, I may still need to drop back a .5 grn to eliminate the sticky bolt.

Do these velocities above seem high for the loads? I am wondering if my scale is off and I am actually loading to much powder?

Just curious as to your load data. Your starting points seem higher than the max in my data.

The two manuals that I have do not even list the STW. I did as much research as a I could on the internet and found that the loads online were between 66.8 to 83 grns. So in my thinking I worked backward from .5 grns over this upper limit down to 79 grns at .5 increaments for a 10 shot ladder test.

I am even getting a sticky bolt while shooting 78.5, 79 and 79.5 grns IMR 7828 150 grn SMK and that is below max for the 78.5 and 79. I was told book max was 79.3. This is a savage with the floating head on the bolt and I don't know if it is just a tight chamber or that I have a ruff chamber and neck or the timing on the bolt is off or this gun just can't take the higher end of the loads. I will work on lower amount of powder and see what that will do. I guess this gun will not get the velocities it should. As time will allow I will try maybe Retumbo or H870

Bob and ramrod what are the velocities either of you are seeing on your proximal loads.

Am I expecting to much from this gun? I know speed is not everything and I will settle on the combination of the most accurate load but at the highest speed I can get. It does seem to shoot very accurate when i get a decent load. I know that the recent elevated ambient outside temperature can play a part on pressures. I was suprised this time that I was having problems ejecting the 78.5 grn load as at the last range time It was shooting no problem and about the same outside temperature.

Harold I have no answer for your hard extraction issue. I've only had a couple cases of hard extraction and I know those were VERY HOT loads. I also have NO experience at all with a savage.

As I said I have a 26" Laredo I get 3400 and a little change from a 140AB. MY load is 83grs of 7828(DO NOT TAKE THIS LOAD AT FACE VALUE!!!!!!)I would not recommend this for anyone!!!!!!!!!!!! THIS LOAD IS 5.5 GRS ABOVE THE 77.5 GR NOSLER BOOK MAXIMUM My rifle was built with a reamer cut to minimum specs. I set the headspace so factory brass is a crush fit and had custom dies made. I made 3 rifles like this and the other 2 could not get 3400. I use 8 mag brass(at the time the STW was a wildcat without factory brass) and I get .0001 head expansion each firing and the load is 1.5gr below .0005 expansion. I toss the brass after the third firing while the case will still hold the primer firmly for the cost of brass it is not worth pushing the life.

I loaded for 35 years and 25 years of heavy wildcating. To me taking someone's max (other than a bullet or powder companies) load off the interent and just backing off 5 grs and working up is going about it backwards. I take the max load listed by a powder or bullet company back off several grains and then work up.

In my case of the 3 rifles cut with the same reamer to the same tight headspace made as close to the same as I could make them what I could call max load was 2+ grs apart.

My own rifles prefer 80gr of 7828 behind a 140gr mrx or ballistic point.I use remington cases and 215 primers.Velocity averages 3500fps with both and the the accuracy is 1/2" with the ballistic point and 5/8" with the mrx.
My own rifles show pressure signs with more than 78gr of 7828 behind a 150gr bullet.

quote:

My own rifles prefer 80gr of 7828 behind a 140gr mrx or ballistic point.I use remington cases and 215 primers

Talk about fast barrel. That is almost 100fps faster than my load using 3rs more powder.

Loadtech calls the 80gr 140 as 3305 @60225 and the 78gr 150 as 3285 @ 59355. While I don't know if you have a slick barrel or simply higher pressure to get your 3500 I'm surprised you see pressure signs with the 150.

Harold,

3350 fps. with the 7828 load and 3375 fps. with the RL-22 load..............

Bob

quote:

Talk about fast barrel. That is almost 100fps faster than my load using 3rs more powder.

Both of my 7mmstw rifles produce the same velocity with 26" barrels.One is a schneider barrel,and the other a Kreiger.The chambers were cut with my own reamer made to minumum specifications.I use a 1 in 10" twist in both barrels.

quote:

Loadtech calls the 80gr 140 as 3305 @60225 and the 78gr 150 as 3285 @ 59355.

The SAAMI pressure for the 7mmstw is 65000psi,so these loads are producing less than design pressure.


http://www.ramshot.com/powders/loadpressure.php

I had a 7mm stw with a 27" hart barrel. My favorite load was a 140 gr partition using RL25 at 3500 fps. I don't have my notes in front of me and can't remember the charge weight. Most book reloading data for the stw is useless, better data is to be found from experienced guys like these here and some experimentation with a chronograph.

quote:

The SAAMI pressure for the 7mmstw is 65000psi,so these loads are producing less than design pressure.

I wouldn't bet to much on how accurate the Loadtech numbers are.

quote:

I wouldn't bet to much on how accurate the Loadtech numbers are.

I wouldn't either,but that doesn't change the fact that the pressures are well below the SAAMI pressure for the cartridge.That at least partly explains the lower velocities.

quote:

I wouldn't either,but that doesn't change the fact that the pressures are well below the SAAMI pressure for the cartridge.That at least partly explains the lower velocities.

I thought your rifle was showing pressure signs with 78grs.

quote:

I thought your rifle was showing pressure signs with 78grs.

My rifles both show pressure signs above 78gr with 150gr bullets,but the velocities are also above 3400fps,so the pressure is almost certainly well above 60,000 psi as well.All rifles do not produce the same velocity or chamber pressure with a given load.You have to take into account variances in powder lots,and variances in chamber and barrel dimensions.
The point that I was making was that the loadtech pressures were well below the SAAMI pressure,so it only makes sense that the velocity was lower than normal as well.

quote:

The point that I was making was that the loadtech pressures were well below the SAAMI pressure,so it only makes sense that the velocity was lower than normal as well.

Ok we are on the same page. Yep no two rifles are the same.

According to one of ramrods first post of me starting my ladder at 1.5grn above book max, I am going to back off the load back to 75 grn and work up until I get my sticky bolt problem or other pressure signs. What is confusing to me is that I was not getting a sticky bolt on three of the ladder shots (80.5,82 and 83.5). I imagine the temperature that day had something to do with the load as well as well as my other loads. If I can get an accurate load for the 140grn Acubond to push +3300 in hot weather I could be happy with that. I will check loads latter this winter to see what changes.

Bob thanks for the info.

Stubble thanks for jumping in here.

Ramrod Your comments have made me rethink my research techniques.

Went to the range to day to work on the H-1000 ladder for the 140 grn Acubond bullet. Weather was cooler low 80's wind out of the 5 o'clock position at about 10-15 mph. Over cast with scattered drizzle around but no on me.

H-1000 140 grn Acubond
81grn 3318
81.5grn 3317
82grn 3339
82.5grn 3334
83grn 3370

No pressure signs and what was strange was that this ladder shot an 1 1/4" size group at 200 yards.

I shot my 78.5 grn of IMR 7828 and 150 grn SMK and though the bolt had resistance on ejecting it was not necessary to tap the bolt back. I guess this one is not a hot weather load. Will drop on down to 78 grn if I stay with the IMR 7828. Average velocity was 3356 with an SD of 18. If I drop down to 78 grn I should still have velocities over 3300 FPS.

I was also running the IMR 7828 140 grn Acubond with lower powder charge.

IMR 7828 140 grn Acubond
77grn 3311
77.5grn 3390
78grn 3407
78.5grn 3386
Stopped here because I had a case head separate. I pulled the case head off when I ejected the round. Ran a cleaning rod and patch to push the case body out of chamber. These cases had been fired 5 times and some of them were from previous ladders and load testing that had sticky ejection issues. There was no evidence of case fatigue and all dimensions of the case measured within specs.


I think I am going to quit chasing the velocity bug and settle for the most accurate load I can get with safe pressures and decent speed.

I am thinking that IMR may be to fast for my chamber/barrel and will just have to live with lower velocities.

I am also going to work more with the H-1000 powder as well, maybe try a slower powder like Retumbo to see if that helps.

Remember guys this is load development and as you can see and as others have pointed out I am and have loaded some hot rounds. Please start off with lower charges and work up.

Harold,

Please forgive me if I've missed something here; I've read this thread and one previous by you (early August.)

Are you still FL sizing, bottoming the shellholder on the Lee die? You seem to describe a lot of case stretch which might be greatly alleviated by some adjustment of your sizing technique(not to mention case head separations.)

Are you measuring case head expansion? It's a good indicator of what the brass can tolerate.

Since your extraction problem appeared, have you shot any (audible gasp) factory ammo? You may have inadvertently "jugged" or swollen your chamber. Extraction problems when firing factory ammo that chambers easily would so indicate.

Bill,

Yes I am still FL sizing. I am bottoming the die to the shell holder.

Yes I am measuring case head expansion and have not seen abnormal measurments, all in spec.

I have some factory Remington Corelocks that I have not fired, I planned on using them as foulers as they shoot about 3 moa. I will try one next time I'm at the range.

My extraction really only happens at the max or over max loads and when temps are above 85 degrees.

Once I find a good safe decent load what can i expect from my case life?

Harold,

Regarding full-length sizing, please read the info at the following URL:

http://www.redding-reloading.com/pages/compshellhldrs.html

It is common for dies to be a less-than-perfect fit to a particular rifle, and the Redding shellholders are a good solution. Using them the press still closes fully, reducing case-to-case variation in length, and you can make your rifle headspace on the case shoulder instead of the belt. This should substantially increase your case life. I suggest you start with new cases.

Case-head expansion is not measured to a specification; it is measured with ONCE-FIRED brass, in the case of the 7STW as the diameter of the belt, at the same point on the diameter (for example, with one anvil of the micrometer over the "7" on the headstamp) immediately before and after the second firing of the cartridge (as soon as it has cooled,) and to a precision of .0001 inch (one ten-thousandth.) This requires a micrometer of good quality with the appropriate graduations. You CANNOT accomplish this with a dial or digital 6" caliper.

To get a case life of 5-6 reliable loadings, which most of us probably consider reasonable for a belted magnum of little sidewall taper, case-head expansion must be limited to a maximum of .0003 per firing or thereabouts. Your rifle will tell you. If new primers enter the pockets with little or no effort before you get to the sixth firing, your load is too hot IN THAT BRASS. Some brands and lots of brass are harder and thicker than others, and will take more pressure before the heads stretch.

I hope you are aware that the internal volume of cartridge cases varies between brands and lots. This makes less difference UNTIL YOU APPROACH MAXIMUM LOADS. Sort and weigh your brass carefully. Approximately eight grains of brass equals one full grain of powder capacity for a given loading.

One more thing for now - be sure that your chamber is clean and fairly smooth. You mentioned some case failures (splits and separations.) These may have left some residue or other roughness behind.

Good luck, and load wisely rather than too well.

Thanks FL for the link and info.