not sure why this is happening

[black_ump]

with 168 hornady match i can shoot a 5 shot group thats 1 moa at 100

the vary same load next 5 are in a 4" group at 100

why is that ?

when i load this is what i do/use

mtm digital powder scale
brass is preped in every way but trimmed i dont have a trimmer
bullets are weighed and sorted
using blc-2 powder

iam going to stop loading/shooting till i get a trimmer and varget powder

but would like to know why ? is it because the barrel is still warm ?

its in my msg90-a2 rifle this happens

 

[Chucky]

Re: not sure why this is happening

It sounds like your barrel is getting warm and it is causing your shot group to open. Next time you are at the range I would shoot a 5 round group wait a couple of minutes and then shoot again and see if your second group is still opening up.

 

[black_ump]

Re: not sure why this is happening

ya i waited about 5 min sould i wait longer ? 20 min maybe 30 min

 

[Chucky]

Re: not sure why this is happening

It seriously sounds like your barrel is warming up and that is why it is throwing shots. Wait 20 minutes then. Or pace your shots when you are shooting your groups.

 

[ORD]

Re: not sure why this is happening

It could be any number of things, but most likely, it is one or a combination of the following:

1) barrel is heating up and causing your groups to open up (out of curiosity, what exactly are your groups doing? Are you getting vertical stringing? Do you just have rounds going every which way but where they should? In my experience, a barrel of the dimensions of your Douglas MSG barrel shouldn't be stringing or opening up 4-5x in that short a course of fire. Try shooting a 5rnd group, waiting at least 15min or more, then shoot another 5rnd group.);

2) reloading errors/inconsistencies/powder issues (the switch to Varget may yield different results);

3) is it possible that after your rifle heats up a little that the barrel is no longer free-floated (making contact with the handguard, etc....this is a real long shot with your setup as I have seen it, but worth a quick glimpse around the rifle once it has heated up a little);

4) operator error/fatigue (no offense intended or disparaging of your abilities...just a possibility).

 

[black_ump]

Re: not sure why this is happening

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">It could be any number of things, but most likely, it is one or a combination of the following:

1) barrel is heating up and causing your groups to open up (out of curiosity, what exactly are your groups doing? Are you getting vertical stringing? Do you just have rounds going every which way but where they should? In my experience, a barrel of the dimensions of your Douglas MSG barrel shouldn't be stringing or opening up 4-5x in that short a course of fire. Try shooting a 5rnd group, waiting at least 15min or more, then shoot another 5rnd group.);

2) reloading errors/inconsistencies/powder issues (the switch to Varget may yield different results);

3) is it possible that after your rifle heats up a little that the barrel is no longer free-floated (making contact with the handguard, etc....this is a real long shot with your setup as I have seen it, but worth a quick glimpse around the rifle once it has heated up a little);

4) operator error/fatigue (no offense intended or disparaging of your abilities...just a possibility). </div></div>


ord,

vary glad to hear from you, my groups are settling in, today i put 4 out of 5 rounds in a quarter and the 5th round was about .5 inch away from the 4 round group, the first group always shoots tight with 1 flyer.

my barrel dimention is the same as a psg-1 barrel only i had my threaded for a g-3 muzzle brake its a heavy .920 all the way from the trunion to the muzzle brake

my powder mesurments have been pretty spot on i measure the powder 3 times befor i put it in the casing but i could be due to my caseings not being trimmed

your # 3 and #4: ill check for #3 but your #4 could be on because after my first group i feel tense i feel tight and i feel stressed, maybe i should get off the bengh and take a walk around and look for brass or somthing to relax me. or just space my shots

out side of the 2nd group being a bit wide the rifle is finnaly settling in

 

[mcm308]

Re: not sure why this is happening

Dump the digital scale and try a mechanical beam scale to weigh the charges. Also could be a variation in case length if your not trimming. Just some things to weed out.

 

[Badshot308]

Re: not sure why this is happening

Chances are if you're feeling tense,tight and stressed after your first group, then the problem is you. You need to remain relaxed and focused. A 5 round group fired out of that heavy barrel shouldn't be causing that much heat to build up. My AR10 barrel doesn't get hot enough to cause a problem unless I fire groups in rapid succession. Did you look at the links to the Lee case trimming tools I posted to you in a previous thread? Very inexpensive and almost foolproof. How many reloads are you getting out of those cases? Cases will grow in length each time they are run through a resizing die. Are you measuring them with dial calipers to make sure they are within the proper range? I wouldn't dump the electronic scale but it is a good idea to have an accurate manual beam scale to check it against. Check weights are also important for verifying the accuracy of both electronic and beam scales and calibrating them.

 

[black_ump]

Re: not sure why this is happening

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Badshot308</div><div class="ubbcode-body">Chances are if you're feeling tense,tight and stressed after your first group, then the problem is you. You need to remain relaxed and focused. A 5 round group fired out of that heavy barrel shouldn't be causing that much heat to build up. My AR10 barrel doesn't get hot enough to cause a problem unless I fire groups in rapid succession. Did you look at the links to the Lee case trimming tools I posted to you in a previous thread? Very inexpensive and almost foolproof. How many reloads are you getting out of those cases? Cases will grow in length each time they are run through a resizing die. Are you measuring them with dial calipers to make sure they are within the proper range? I wouldn't dump the electronic scale but it is a good idea to have an accurate manual beam scale to check it against. Check weights are also important for verifying the accuracy of both electronic and beam scales and calibrating them. </div></div>

yes i sure did get the link and yea i like them, i just watched a youtube vid on the forster lathe trimmer with the 3 in 1 cutter does lenth and inside out side champer and i must say i am vary intrested in that one .

my scale is electric and i do calibrate it every time i use it.... mtm is sending me a new one because some times this one wont go to certin 10's of a grain. so ill have a new one soon

though about getting that scale where you just type the grain in and it spits it out on its own not sure who makes it though

and ya i think i just need to pace my shots or wait a good 15 min or just walk the stress out of me or somthing

 

[LongShot94]

Re: not sure why this is happening

Try shooting a 10 round group and see if starts to open up after the first 5.