Rifling Marks??

[Jackalope33B]

Ok, just got back from the range............ again!
For some damn reason I cant seem to hold a group for shit @ 100 yards. Some shots are dead on, others are off an inch or two either up, down left and right.
Im using Varget powder, SMK BTHP 175gr bullets, Federal 210M primers, and winchester brass. Brass is trimmed to 2.007 +/-. After seating the bullet using a Redding Comp die, Im getting a measurement of roughly 2.803 +/-. The varget loads Im using was 40, 40.5, 41, 41.5. It was with all these loads that Im having issues with.

BTW, how much variance will you get measuring from the TIP of the bullet to the case head VS using a Bullet Comparator?
I noticed that when I went to chamber the 2 rounds in the listed pictures below, the bolt handle was a little tough to close, but I did close it. Upon extracting the rounds, I noticed about 1/8" above the case neck there was a "gouge" that was perfectly straight going across the bullets. Is this where the rifling was touching the bullets?

 

[davidslife1975]

Re: Rifling Marks??

i am new here but i had a problem like this and it wasnt the ammo one of mt scope rings were loose tightened it up and i shot right again

 

[Jackalope33B]

Re: Rifling Marks??

Everything on the scope is snug and tight.

 

[flounderv2]

Re: Rifling Marks??

What is your neck tension. To me that seems almost like you crammed the bullets into the lans on chambering and they were pulled out of the case a bit when you ejected them. Have you measured you from base to ogive before chambering and then after you ejected the rounds.

 

[mgoodrich]

Re: Rifling Marks??

I haven't reloaded for the 308 yet, (I am assuming this from your description). I have a gun on order so will be shortly.

Yes, it seems from your description you are going into the rifling, which I do not do when I am starting to develop a load.

I would back off about 25mil, and then shoot a ladder. With that bullet, most of the things I have read, they like to have a load of Varget between 43 an 44 gr, so your powder seems to be a bit light.

After getting the best powder charge, I then experiment with the seating depth. The optimum seems to be between 5 to 18mil jump to lands.

The more experienced guys with the 308 will jump in here a bit.

This is what I do on my guns. A lot of the times though the first load I pick after reading up tends to work good enough for me, so I don't have to go through that on every gun.

 

[Jackalope33B]

Re: Rifling Marks??

I dont have a tool to measure neck tension. Im using a FL Die for my brass. I cant say that I did "cram" the bullet into the lans. When I push the bolt FWD, I do it nice and easy. There is no full force. No, I didnt measure to the Ogive. I need to get that tool from Sinclair's..
I just measured the rounds in the pictures. They are not any shorter or longer from when I measured them after seating the bullet.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flounderv2</div><div class="ubbcode-body">What is your neck tension. To me that seems almost like you crammed the bullets into the lans on chambering and they were pulled out of the case a bit when you ejected them. Have you measured you from base to ogive before chambering and then after you ejected the rounds. </div></div>

 

[Muttt]

Re: Rifling Marks??

Whenever I see rifling marks on my bullets, the marks usually show the lands and groves. I'm thinking the solid ring is from something esle. But, that's only an opinion.

But, if you truely are hitting the rifling with the bullet, it might be holding the bullet when you pull the round back out of the chamber and it could have tugged the bullet out of your case. The solid ring is probably where the bullet was seated in the brass.


Edited To Add: Now that I look closer at your pic. I can see the land marks on the bullet on the right side of the picture. It looks like you did jam it into the lands. The lands where holding the bullet when you ejected the round and pulled it out a tiny bit. I bet if you measure a newly loaded round and compared it to this one, you'll find it is now longer.

 

[Jackalope33B]

Re: Rifling Marks??

Yes, it is a .308, sorry about that.. As far as the Varget being a little light, well, thats another issue I was having a few weeks ago (http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=3005006)
That is a long post about my issues with possibly HOT loads, Primer Issues etc etc etc. This is why Im starting my loads "light".. At 43gr+ of Varget, the rifle kicks like a SOB, and then I was seeing issues with flattend primers, ejector marks etc..

Im about to throw the towel in and say fu*k it all. Im spending way too much $$ on making a bullet, and I cant hit dick with it none the less enjoy a day at the range lol.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgoodrich</div><div class="ubbcode-body">I haven't reloaded for the 308 yet, (I am assuming this from your description). I have a gun on order so will be shortly.

Yes, it seems from your description you are going into the rifling, which I do not do when I am starting to develop a load.

I would back off about 25mil, and then shoot a ladder. With that bullet, most of the things I have read, they like to have a load of Varget between 43 an 44 gr, so your powder seems to be a bit light.

After getting the best powder charge, I then experiment with the seating depth. The optimum seems to be between 5 to 18mil jump to lands.

The more experienced guys with the 308 will jump in here a bit.

This is what I do on my guns. A lot of the times though the first load I pick after reading up tends to work good enough for me, so I don't have to go through that on every gun. </div></div>

 

[Jackalope33B]

Re: Rifling Marks??

The thing is, the bullet seating depth has not changed. Im not crimping my rounds or anything.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Muttt</div><div class="ubbcode-body">Whenever I see rifling marks on my bullets, the marks usually show the lands and groves. I'm thinking the solid ring is from something esle. But, that's only an opinion.

But, if you truely are hitting the rifling with the bullet, it might be holding the bullet when you pull the round back out of the chamber and it could have tugged the bullet out of your case. The solid ring is probably where the bullet was seated in the brass. </div></div>

 

[Muttt]

Re: Rifling Marks??

What is your seating depth??


It looks like all you need to do is seat the bullet about another .020 deeper in the case. If you don't have a pair of quality calipers, you need to get one. You can get a nice set for under 30.00 bucks a Harbor Frieght.

Do you know the max length you can load that bullet?? It's really a simple process to find out what you max loading length is with a particular bullet. Here's a good thread that explain it .........

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1705470#Post1705470


Don't throw in the towel. Once you figure it out, the results are well worth the effort. I had all kinds of problems with my first load. Some of it was from not sizing correctly. Then, I was messing up seating length. Once I got all that figured out, my loads really worked well.

Once you get your bullets out of the lands, your problems with too hot a load may go away also. If you have your bullet jammed up into the lands, it can cause the pressure to rise to high before the bullet gets going down the barrel. I think once your fix your seating depth, you other problems will get better.

 

[Jackalope33B]

Re: Rifling Marks??

My seating depth is 2.801 +/- a few thousandths. Im using a Digital Calipers to get my reading. Every now and then Ill close them and "ZERO" them out just to make sure they are tracking right. I have some "rod stops" in bound for my cleaning rod to find out the overall length I need to seat the bullet into the case.


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Muttt</div><div class="ubbcode-body">What is your seating depth??


It looks like all you need to do is seat the bullet about another .020 deeper in the case. If you don't have a pair of quality calipers, you need to get one. You can get a nice set for under 30.00 bucks a Harbor Frieght.

Do you know the max length you can load that bullet?? It's really a simple process to find out what you max loading length is with a particular bullet. Here's a good thread that explain it .........

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1705470#Post1705470


Don't throw in the towel. Once you figure it out, the results are well worth the effort. I had all kinds of problems with my first load. Some of it was from not sizing correctly. Then, I was messing up seating length. Once I got all that figured out, my loads really worked well.

Once you get your bullets out of the lands, your problems with too hot a load may go away also. If you have your bullet jammed up into the lands, it can cause the pressure to rise to high before the bullet gets going down the barrel. I think once your fix your seating depth, you other problems will get better. </div></div>

 

[mgoodrich]

Re: Rifling Marks??

+2 on what Mutt said.

I know it can be frustrating though. I have a 22-250 savage that I am having issues with right now, so I understand.

I read through the other thread, and it does look like to me you need to start by ajdusting down your seating depth. Try going to around 2.77 COAL, Load up about 4 or 5 and shoot them with the 41.5 gr. See how those feel to you.

 

[Jackalope33B]

Re: Rifling Marks??

Ok, I just measured from the top of the case neck to where you see those small "gouges". My reading was .049.. So if I understand you correctly Turning my DIE down .049 will "roughly" give me a starting point for my bullet touching the lands? I know this is not the best way to go about finding your starting length, but am I in the ball park to start seating my bullets to 2.751?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jackalope33B</div><div class="ubbcode-body">My seating depth is 2.801 +/- a few thousandths. Im using a Digital Calipers to get my reading. Every now and then Ill close them and "ZERO" them out just to make sure they are tracking right. I have some "rod stops" in bound for my cleaning rod to find out the overall length I need to seat the bullet into the case.


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Muttt</div><div class="ubbcode-body">What is your seating depth??


It looks like all you need to do is seat the bullet about another .020 deeper in the case. If you don't have a pair of quality calipers, you need to get one. You can get a nice set for under 30.00 bucks a Harbor Frieght.

Do you know the max length you can load that bullet?? It's really a simple process to find out what you max loading length is with a particular bullet. Here's a good thread that explain it .........

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1705470#Post1705470


Don't throw in the towel. Once you figure it out, the results are well worth the effort. I had all kinds of problems with my first load. Some of it was from not sizing correctly. Then, I was messing up seating length. Once I got all that figured out, my loads really worked well.

Once you get your bullets out of the lands, your problems with too hot a load may go away also. If you have your bullet jammed up into the lands, it can cause the pressure to rise to high before the bullet gets going down the barrel. I think once your fix your seating depth, you other problems will get better. </div></div> </div></div>

 

[crewchef]

Re: Rifling Marks??

I remember your other thread but not all the details. I asked over in that one but never saw a response, custom or factory barrel? If it's factory and correct, the 175s won't touch the lands when seated to max COL (2.810) and you're just short of that.

At best this is a SWAG without actually being able to see the rifle and do some measuring but it certainly seems like there is a potential chamber issue. Have you tried factory rounds like FGMM w/ 175s? Same feel when you close the bolt, same marks on bullet? If not, measure the COL and shoulder on the factory round and compare to yours to make sure you're measuring correctly. FGMM loads should work in any SAMMI spec chamber.

Measure the neck of fired brass and then loaded round. A factory barrel will probably have .007/.009 difference. If it's the same size (bad) or very close (.002/.003) (tight neck chamber) then you can go from there. If it's factory barrel, get them to fix it. If it's custom then talk to your smith and/or prep brass for it by neck turning.

Don't give up on it, the answer is here just have to work through the steps to find it. First steps are getting the measurements on rifle and brass to understand how they're fitting together.

 

[treymchattie]

Re: Rifling Marks??

a quick and easy way to be sure that you arent driving the bullet into the rifling is to take a sized case (with no primer or powder), using a dremel tool cut 4 slots from the neck down to the bottom of the shoulder so that a bullet can move with a bit of downward pressure but wont fall out. stick a bullet just into the neck and close your bolt on it, extract and measure. do this a few times to be certain.

i was surprised to find that i was seating far too deep for my rifle.

 

[Jackalope33B]

Re: Rifling Marks??

I did try the 4 slit method as you described. I came up with seating depth of 2.799.5 .. So I had planned to seat about .003 into the lands.. But as you can see, this didnt help me much.. I need to get a Bullet Comparator that measure to the ogive. I keep reading that the tips on these bullets are soo out of spec..

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treymchattie</div><div class="ubbcode-body">a quick and easy way to be sure that you arent driving the bullet into the rifling is to take a sized case (with no primer or powder), using a dremel tool cut 4 slots from the neck down to the bottom of the shoulder so that a bullet can move with a bit of downward pressure but wont fall out. stick a bullet just into the neck and close your bolt on it, extract and measure. do this a few times to be certain.

i was surprised to find that i was seating far too deep for my rifle. </div></div>

 

[Seth8541]

Re: Rifling Marks??

Those powder charges seem REALLY light to me. That may be your issue. Start at 43 and move up in .3 gn increments to just over max and stop when you see signs of pressure. Probably gonna shoot a lot better between 43.5 and 44.5 gns. JMO

 

[jkonzal]

Re: Rifling Marks??

You might want to invest in an O.A.L. gauge. Check it 6-8 times to make sure you get consistent readings. I use the Hornady.

 

[Jackalope33B]

Re: Rifling Marks??

Read this.. I was having pressure issues http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=3005006


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Seth8541</div><div class="ubbcode-body">Those powder charges seem REALLY light to me. That may be your issue. Start at 43 and move up in .3 gn increments to just over max and stop when you see signs of pressure. Probably gonna shoot a lot better between 43.5 and 44.5 gns. JMO
</div></div>

 

[Muttt]

Re: Rifling Marks??

Hope it works out. let us know how it goes. I think once you get a good reading for your chamber, then the rest will work itself out. If you figure out your length I'd go back to the begining working up your loads starting with the minimum load.

 

[gvanhyning]

Re: Rifling Marks??

I have some recommendations ... first I would reduce the charge increments down to .2-.3 grains instead of .5. This makes it easier for find that sweet spot in charge weight. Next, get a bullet comparator to use with your calipers. This will allow you to measure bullet length to the ogive which will ensure a uniform "jump" to the lands. Bullet lengths are never consistent and can lead to various seating depths which can affect a lot of important variables. When I developed a load for my .308, I bought a box of Federal match ammo and measured them for length using a comparator. That gave me a good starting point for OAL in the load development. One last note, remember that you are developing a load for your gun and not every shot is going to hit the POA. You are looking for grouping in your initial shots. Find the best group and fine tune it from there. Hope this helps. I'm not sure what would have marked the bullet you have pictures of.

 

[armorpl8chikn]

Re: Rifling Marks??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treymchattie</div><div class="ubbcode-body">a quick and easy way to be sure that you arent driving the bullet into the rifling is to take a sized case (with no primer or powder), using a dremel tool cut 4 slots from the neck down to the bottom of the shoulder so that a bullet can move with a bit of downward pressure but wont fall out. stick a bullet just into the neck and close your bolt on it, extract and measure. do this a few times to be certain.

i was surprised to find that i was seating far too deep for my rifle. </div></div>

THIS^^^^
I have posted this a few times here myself. I was talking on the phone with my spotter/gunsmith earlier and he does it this way as well as I already knew but he added a little bit I hadn't thought of...
Get a large nut from the hardware store lets say 1". Take a 9/32 drill bit and drill a hole through the flat to the center. Viola, a homemade comparator for $.50. Now combine this with the split neck case trick and you have a poor man's setup that is just as accurate as you will ever need....trust me.
PS: a fired and minimally resized case works best for this. Set up your FL die to just size most of the way down the neck then split. I only use two splits.

 

[MAT4-82]

Re: Rifling Marks??

If it were me I would go purchase a box of Federal Match ammo and establish a standard. Those loads should shoot better than that generally. I suspect something else.

 

[Jackalope33B]

Re: Rifling Marks??

Ok, so I seated one of the rounds about .075" deeper in to the shell, took a black sharpie marker and covered the "gouge". I then rechambered the round. It was once again a little hard to close the bolt as it was before. I then extracted the round and where the black sharpie was covering the "gouge", I saw there was another "gouge" about .075" higher (towards the tip) WTF?!?!

 

[Jackalope33B]

Re: Rifling Marks??

just got done taking the rounds apart. I measure every where you can on the bullets I was having issues with and new ones in the box. the measurements are the same for all the bullets. im starting to think that these 2 bullets have a "high" spot on them, and Im not catching it with the micrometer.. UGHHHHHHHHHHHHHHH

 

[armorpl8chikn]

Re: Rifling Marks??

That is an extraction mark on the sharpie colored bullet this time. Are you lubing the necks when you resize? Just spitballin here. Have you made a split case like described above to get an idea of where the lands actaully are? I have had hard chambering rounds before after FL sizing and doing everything right. If you know where your lands start, then you can know that isn't the problem. This case may have not been set back enough or the expander ball may have pulled the neck out just enough to cause hard chambering. If you can close the bolt just fire it if you know the load to be safe.

 

[armorpl8chikn]

Re: Rifling Marks??

Is the empty piece of brass hard to chamber?

 

[Jackalope33B]

Re: Rifling Marks??

nope

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armorpl8chikn</div><div class="ubbcode-body">Is the empty piece of brass hard to chamber? </div></div>

 

[Kevlars]

Re: Rifling Marks??

I would get some match ammo and establish a base line. And that will also rule out your rifle. That would be the first step. IMHO

 

[Jackalope33B]

Re: Rifling Marks??

Im not following here "That is an extraction mark on the Yes, I did the split head case. Measured it, and got +/- 2.799. I am measuring from the tip to case head. I need to get a bullet comparator for better measurements.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armorpl8chikn</div><div class="ubbcode-body">That is an extraction mark on the sharpie colored bullet this time. Are you lubing the necks when you resize? Just spitballin here. Have you made a split case like described above to get an idea of where the lands actaully are? I have had hard chambering rounds before after FL sizing and doing everything right. If you know where your lands start, then you can know that isn't the problem. This case may have not been set back enough or the expander ball may have pulled the neck out just enough to cause hard chambering. If you can close the bolt just fire it if you know the load to be safe. </div></div>

 

[armorpl8chikn]

Re: Rifling Marks??

You didn't split the head of the case did you? We told you to split the neck down to shoulder. Where your bullet goes...in the neck.
Yes an extraction mark. When you do this operation you need to be careful on extracting and when you get the bolt back a little way, stick your finger in there and hold the dummy round so the ejector doesn't push the case against the side of the action. I bet money that is what is making the mark. Best thing to do is take the ejector button out of the bolt for this operation. Careful it doesn't fly accross the room if you try to take it out.

 

[999yards]

Re: Rifling Marks??

Sounds to me like the chamber is just a little too short (at the very minimum of SAMI spec).

the loaded round may be touching the begining of the lead causing the neck to "crimp" the bullet which is still in the lands. When you extract the loaded round a mark is then visible because the bullet pulled from the case.

I would try to trim the neck length and seat the bullet deeper.

If you take the firring pin out you just might feel the case neck contact the lead. Either way take the firring pin out when trying to feel the case. Removing the pin takes all the tension off the bolt when it cams.

Keep us posted.

 

[Jackalope33B]

Re: Rifling Marks??

No, I didnt split the head of the case. I marked the shell with a sharpie and inserted the round into the chamber. I extracted it and noticed the marks on the bullet. i put the round in the chamber again, but this time I make sure I rotated it 180deg. when I extracted the round, the marks were in the same exact place on the bullet. The buller was "sharpied" both times, so I could tell there were fresh marks on there.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armorpl8chikn</div><div class="ubbcode-body">You didn't split the head of the case did you? We told you to split the neck down to shoulder. Where your bullet goes...in the neck.
Yes an extraction mark. When you do this operation you need to be careful on extracting and when you get the bolt back a little way, stick your finger in there and hold the dummy round so the ejector doesn't push the case against the side of the action. I bet money that is what is making the mark. Best thing to do is take the ejector button out of the bolt for this operation. Careful it doesn't fly accross the room if you try to take it out. </div></div>

 

[Jackalope33B]

Re: Rifling Marks??

After talking to some folks at the range, it was the majority that said it was not rifleing marks. what dug that perfect fine groove was "possibly" a built up hard ring of copper and carbon in front of the chamber. I use a bore guide everytime I clean my barrel. Im guessing there is a possibility that my cleaning never touched the front of the chamber, therefor it caused that perfect ring of copper and carbon. Also a cause for this was that these 2 bullets were .0005 of an inch to big.

Any ideas?

 

[Leaddog]

Re: Rifling Marks??

Lot's of advice in this thread. Some good, some not so good. Take your rifle to a good gunsmith and have him look inside with a borescope and measure everything for you. He'll be able to tell you exactly what is going on.

Take your press and your Seater die with you and some unprimed brass and some bullets. He can set a dummy round up for you at the exact contact of the lands for your future reference. Btw.... 175 SMK's like a .010-.015 jump in most rifles.

For your own safety, you are done shooting this rifle until a gunsmith looks at it.