GGG problem

Anything shooting related including law and procedure questions.

Moderator: dromia

Forum rules
Should your post be in Grumpy Old Men? This area is for general shooting related posts only please.
Post Reply
Message
Author
User avatar
shugie
Past Supporter
Posts: 1602
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

GGG problem

#1 Post by shugie »

I was enjoying myself at 600 yards on Century yesterday with some ammunition I'd made using vihtavuori, the results were more than acceptable, my best score ever and by some margin. But I'd not cooked enough of them , and reverted back to my usual GGG from the range office. I've had consistent results with GGG in my Swing, and was more than surprised to find it was all over the place, one round under the target, and no noticeable grouping. I can understand why it might land in a different place, but would at least have expected them all to land, more or less, in the same place.

I'm puzzled.
Careful now/that sort of thing
User avatar
Mattnall
Site Supporter Since 2016
Posts: 2858
Joined: Wed Mar 06, 2013 5:32 pm
Home club or Range: Harlow TAC, NRA, BSRC
Contact:

Re: GGG problem

#2 Post by Mattnall »

Changing ammo can have a dramatic affect on group size until the barrel gets mucky with the new fouling. I have found on changing ammo types I need to shoot 5-10 shots before they start grouping anywhere near I know they should.
Could this have been the issue?
Arming the Country, one gun at a time.

Good deals with Paul101, Charlotte the flyer, majordisorder, Charlie Muggins, among others. Thanks everybody.
hitchphil
Posts: 903
Joined: Thu Jul 05, 2012 11:56 pm
Home club or Range: Bisley - Mostly
Contact:

Re: GGG problem

#3 Post by hitchphil »

.......which bullets in the home load? SMK 2215 or 2216 or X? & what NRA GGG? 147 MilSurp or NRA TR 155?

I have seen the MilSurp 147 GGG perform very poor groups vs GGG155 or RG 155
Quality control of Scottish Ethanol. & RDX/HMX

& my fav chemical is :-) 1,3,7-trimethylxanthine.......... used to kill frogs.... but widely consumed & in vast quantities by the French? Eh?
User avatar
shugie
Past Supporter
Posts: 1602
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: GGG problem

#4 Post by shugie »

Home load SMK2156, GGG 155 match. My Swing has a non-standard Border barrel that only really likes 155.
Careful now/that sort of thing
User avatar
Pete
Past Supporter
Posts: 2947
Joined: Tue Sep 15, 2015 8:48 am
Home club or Range: NRA Bisley
Contact:

Re: GGG problem

#5 Post by Pete »

Non-standard barrel? What twist? My Swing has a 1:11 Bartlein and I get the best results with 2155's, or 155 Scenars.
2156's were never as good.

Pete
"Tantum religio potuit suadere malorum" Lucretius
You're offended? Please explain why your inability to control your emotions translates into me having to censor my opinions....
User avatar
shugie
Past Supporter
Posts: 1602
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: GGG problem

#6 Post by shugie »

Pete wrote:Non-standard barrel? What twist? My Swing has a 1:11 Bartlein and I get the best results with 2155's, or 155 Scenars.
2156's were never as good.

Pete
I don't know what the twist is, the only markings on the barrel are GI.309 F.300 Z.3070
Careful now/that sort of thing
User avatar
breacher
Posts: 3475
Joined: Tue Jan 01, 2013 8:32 pm
Home club or Range: EBSC
Location: Cambridgeshire

Re: GGG problem

#7 Post by breacher »

Mattnall wrote:Changing ammo can have a dramatic affect on group size until the barrel gets mucky with the new fouling. I have found on changing ammo types I need to shoot 5-10 shots before they start grouping anywhere near I know they should.
Could this have been the issue?
This !!!

Very frustrating too.
http://www.phoenixtactical.co.uk

RFD 2043 Cambridgeshire
User avatar
shugie
Past Supporter
Posts: 1602
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: GGG problem

#8 Post by shugie »

breacher wrote:
Mattnall wrote:Changing ammo can have a dramatic affect on group size until the barrel gets mucky with the new fouling. I have found on changing ammo types I need to shoot 5-10 shots before they start grouping anywhere near I know they should.
Could this have been the issue?
This !!!

Very frustrating too.
That's new to me. Could be the explanation, certainly better than anything else I can think of, thanks!
Careful now/that sort of thing
User avatar
Mattnall
Site Supporter Since 2016
Posts: 2858
Joined: Wed Mar 06, 2013 5:32 pm
Home club or Range: Harlow TAC, NRA, BSRC
Contact:

Re: GGG problem

#9 Post by Mattnall »

shugie wrote:
breacher wrote:
Mattnall wrote:Changing ammo can have a dramatic affect on group size until the barrel gets mucky with the new fouling. I have found on changing ammo types I need to shoot 5-10 shots before they start grouping anywhere near I know they should.
Could this have been the issue?
This !!!

Very frustrating too.
That's new to me. Could be the explanation, certainly better than anything else I can think of, thanks!
I've found it's particularly bad with 22LR ammo as well. I guess smaller, slower bullets are affected more by the changes.
Arming the Country, one gun at a time.

Good deals with Paul101, Charlotte the flyer, majordisorder, Charlie Muggins, among others. Thanks everybody.
Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests