7mm Sherman Short Magnum/ 190 A-tip

[gman47564]

Mix a old lot with a new lot and you get a new old lot?

[rardoin]

And you don't get a plaque 

[gman47564]

Lesson learned.. class is over kids... lol

[jvw2008]

" I mixed a 2015 lot with a 2018 lot."

I have added fresh to old using the same lot but it's made me anxious to do so. Ever notice the loss of chemical odor in powder that has lost its vacuum seal for a couple weeks? Makes me wonder about burn rate in the unfresh powder.

[DHuffman]

" I mixed a 2015 lot with a 2018 lot."

I have added fresh to old using the same lot but it's made me anxious to do so. Ever notice the loss of chemical odor in powder that has lost its vacuum seal for a couple weeks? Makes me wonder about burn rate in the unfresh powder.

I know a guy who opens a new jug and dumps it out on a large sheet of plastic and airs it out for a day or two to let the either evaporate off. He claims it makes it more consistent from start to finish.

[DHuffman]

And you don't get a plaque 

When I get to the end of an eight pounder and there's not enough left to shoot (much less than a #) another match it goes into the next jug and gets a thorough mixing.
I won't mix say 4# of one lot and 4# of a another lot especially if they burn different. I don't want to end up with a mystery lot that may be inconsistent from the mixing.

[jvw2008]

I know a guy who opens a new jug and dumps it out on a large sheet of plastic and airs it out for a day or two to let the either evaporate off. He claims it makes it more consistent from start to finish.

Sounds like a benchresters!  ?

[rardoin]

Update on my 7 Sherman Short.  I had a second barrel spun up, threaded for a Bramley tuner, that was chambered with a different reamer than the first barrel.  This chamber does not play well with the sizing die I have so I set it aside and continued to shoot matches with the first barrel.  I finally had my JGS reamer made with a proper freebore for the 190 A-tips (.325"  ) and rechambered the second barrel.  I could get great 4 shot groups at 300yds quite often....but...unfortunately five shots were sent downrange.  I was getting the old 4 in/one out.  Since I could get 4/5 shots in about .3-.5" quite often with the oddball being at 1"-1.25" out and in the middle a sub .75" 5 shot group I knew the barrel would shoot decent if I could find the right mix.  However I had a few important matches and the combination of lack of time and poor weather kept me from finding a load that I really trusted and had a broad powder window like my first barrel.  At a recent 2 day match I was presented with the dilemma of shooting the old barrel with 1627rds down the tube or shoot the new barrel that could get under .3MOA but open up with .2gr of powder on wither side.  I decided to roll the dice and shoot old faithful.  By the last match on day 2 it shot a 199-11X at 1000yds with the '9' being just outside of the 10 ring at 1:30.  Certainly this barrel has outlived its expected life by 400rds.  All my friends who have experience with the 7 SAUM/180-195gr bullets said 1200 rounds likely with 1400rds being the max.  The last match put her just shy of 1800rds but can still haul the mail.  I hope this is not a fluke and I can count on 1500+rd barrels.

[DHuffman]

You racked up some lettuce and knowledge with that barrel Robin. Nice effort putting in the work to develop it out. I suspect you are going to compete against some similar gear in the near future.

Well done my friend!

[rardoin]

Thanks Dave.  I already had two other shooters in the mentioned Georgia LR match shooting 7 SAUM variants with 190 A-tips.  One of them was the wind coach for the team when we won the Tx LR team championship; he saw how well they did in the tropical storm conditions we shot in and the following 600yd championship in heavy weather.  Several others I know have tried them and bailed because they could not get them to shoot well enough in their set-ups.  The few that I shoot with who have made them work have set aside their .300 WSM/variants.