Issue with New Dies

[Bruce Wambach]

Hi

I’m new here to forum. Been reloading for several years now and am stumped on something with a new set of dies. Kindly ask for your input, please.

Rifle is Ruger M77 Mark II .30-06
Load is 50gr IMR 4895, 150gr Sierra HPBT, Winchester case, Win LR primer

At 200yds the above would print three holes like a clover. The dies I used were borrowed from a relative (I was just getting into reloading). They were a 1970s Lyman collette type FL. I’m nearing the end of that run and now have a set of RCBS FL dies. Same gun, same load and here’s what I’m seeing…1) group has opened up slightly and 2) group is not printing at same point of impact as original loads in the Lyman dies.

Could it be the neck sizing is different between the dies and it’s changing my pressure?

I would greatly appreciate any input y’all might have, as it’s gotten a little frustrating.

Bruce, SC

 

[Blue68f100]

Could be a couple of things. Neck tension as you suggested and over all general sizing. Having the shoulder at a different position may also cause it. Also the more times you reload a case you work harden it so spring back is less. Are you sure your Lyman die in not a Neck sizing only?

Measure your neck size between the 2 dies may tell you whats happening. Also measure your shoulder position to see if the RCBS die is moving it to a different position.

 

[JFrank]

Yeah it could be in the neck tension/ bullet hold, but in general terms how long has it been since the load was originally tuned and which components are new lot numbers ? When’s the last time the barrel had a good scrubbing ?
Tune doesn’t last forever, climates change, wind blows , altitude plays a small part. case capacity may be different as guys sometimes use range brass also guys get wrapped up on a good group but it does always repeat due to chasing group size rather than point of impact.
Just a few thoughts..

 

[jmorris]

Could be just the way the dies are set or any number of other variables from the exact components used, all the way down to the different days you shot.

 

[Bruce Wambach]

Thank you both! There are a lot of variables to be sure. Sadly I don’t have access to those Lyman dies as they are 9hrs away from where we live now. So, climate, altitude like you said could now be a factor.

This rifle probably has another 75-100 rounds through it now and even though it has been cleaned good, there’s another factor to contend with maybe that I wasn’t considering. The rifle was new (maybe 25 - 35 rounds through it) until I had that grouping mentioned above.

Powder is a newer batch, bullets and primers are the same.

I appreciate you guys chiming in this morning!

 

[Milt1]

May not have anything to do with reloading! Could be that your scope mount is loose in some area, it doesn't take much to throw it off!

 

[AJC1]

Thank you both! There are a lot of variables to be sure. Sadly I don’t have access to those Lyman dies as they are 9hrs away from where we live now. So, climate, altitude like you said could now be a factor.

This rifle probably has another 75-100 rounds through it now and even though it has been cleaned good, there’s another factor to contend with maybe that I wasn’t considering. The rifle was new (maybe 25 - 35 rounds through it) until I had that grouping mentioned above.

Powder is a newer batch, bullets and primers are the same.

I appreciate you guys chiming in this morning!

A gun barrel is dynamic and changes most in the first 100 or so rounds. Your not done breaking it in yet so the load may need a little tuning as you go. Your brass is also being fire formed and growing in length giving you a small amount of additional capacity. You may find with the same lot of.powder you need to up the load a few tenths. New bottle of powder can go either way a few tenths.

 

[Thomasss]

Sometimes, as others have stated, it can be the most simple of changes. I have two sets of dies for each caliber. One set for each rifle. 30.06 and .270. RBCS from 1970 and 2005 from Hornady Custom Taper. When is the last time you cleaned your dies? Have you changed powder LOTS lately? New box of bullets? Do you weigh your bullets? I found a few 150 grain bullets in a box of 165 labelled box of bullets. S*** happens. Your never mentioned where you seat your bullets or where you trim you cases. I've gone back to doing a lot of that by hand cause the auto trimmers do get dull over time. Go back to start. Do not pass Go. Do not collect $200 and take a serious look at each step and look at what might be an issue and let us know what you find.

 

[mdi]

I like reloading so "redundancy" isn't a problem for me. I would start anew. Double check die adjustments and do another load work up. Works for me...

 

[Taurus 617 CCW]

Many variables are at play as others have mentioned. One thing I have not seen recommended yet is checking your loaded rounds with a minimum chamber spec cartridge gauge. At the very least it will tell you if the brass has been properly sized. Beyond that (and starting over with dialing in your loads), you might try a different set of dies. Perhaps a set from Lyman or Lee. If you get better results from different dies then you have found the variable.

 

[GeoDudeFlorida]

Hi

I’m new here to forum. Been reloading for several years now and am stumped on something with a new set of dies. Kindly ask for your input, please.

Rifle is Ruger M77 Mark II .30-06
Load is 50gr IMR 4895, 150gr Sierra HPBT, Winchester case, Win LR primer

At 200yds the above would print three holes like a clover. The dies I used were borrowed from a relative (I was just getting into reloading). They were a 1970s Lyman collette type FL. I’m nearing the end of that run and now have a set of RCBS FL dies. Same gun, same load and here’s what I’m seeing…1) group has opened up slightly and 2) group is not printing at same point of impact as original loads in the Lyman dies.

Could it be the neck sizing is different between the dies and it’s changing my pressure?

I would greatly appreciate any input y’all might have, as it’s gotten a little frustrating.

Bruce, SC

Just me but if I had great results from Brand X I wouldn’t replace them with Brand Y.
IOW: Go buy a set of Lyman dies to match what you used previous with such great success.

 

[ms6852]

When my 30-06 begins to open up first thing I check is the action on my rifle. On several occasions the screws will loosen even after using loctite, especially if the stock is wood. Secondly I give the chamber and barrel a good scrubbing to ensure all lead or copper has been removed. Third I check the mounts on my scope. After I have done all three, I than consider that manufacturing has changed the recipe on their powder and and primers affecting the pressures and harmonics of the barrel, so I begin to reload a new recipe until I find the nodes the barrel likes. Always go back to basics.

 

[AJC1]

When my 30-06 begins to open up first thing I check is the action on my rifle. On several occasions the screws will loosen even after using loctite, especially if the stock is wood. Secondly I give the chamber and barrel a good scrubbing to ensure all lead or copper has been removed. Third I check the mounts on my scope. After I have done all three, I than consider that manufacturing has changed the recipe on their powder and and primers affecting the pressures and harmonics of the barrel, so I begin to reload a new recipe until I find the nodes the barrel likes. Always go back to basics.

Based on his round count only a retorque of the main action screws might help.

 

[Bruce Wambach]

Alright guys I have an update! Appreciate everyone’s comments and feedback.

1) went through the rifle: action, scope mounts…everything was tight as as it should be.

2) here’s where I think the problem happened…it was the cases I believe. I dug out “once fired” Winchester (my original case load) and “once fired Remington cases (the R-P cases grouped well originally just not as tight as Win.) I loaded three of each and took out three of my original loads from the Lyman dies.

Here are the results:

1) original loads, Lyman dies printed and grouped where they should on target.

2) Win cases with through RCBS dies grouped nice and tight and 2” left of aimed point of impact

3) R-P cases through RCBS dies grouped even tighter than the Win’s but about 2.5” left of aimed point of impact

What this tells me is that the dies DO make a point of impact difference, no problem there just a minor scope adjustment. But what’s more important are cycling out cases that even though they look good and have not stretched, there’s still a tensile factor in the brass itself (heating/cooling, reforming, etc) that were at the root of my grouping issue. Someone with more physics knowledge would better explain my layman’s jargon.

Appreciated all the feedback, it helped the gears to get turning.

 

[JFrank]

Alright guys I have an update! Appreciate everyone’s comments and feedback.

1) went through the rifle: action, scope mounts…everything was tight as as it should be.

2) here’s where I think the problem happened…it was the cases I believe. I dug out “once fired” Winchester (my original case load) and “once fired Remington cases (the R-P cases grouped well originally just not as tight as Win.) I loaded three of each and took out three of my original loads from the Lyman dies.

Here are the results:

1) original loads, Lyman dies printed and grouped where they should on target.

2) Win cases with through RCBS dies grouped nice and tight and 2” left of aimed point of impact

3) R-P cases through RCBS dies grouped even tighter than the Win’s but about 2.5” left of aimed point of impact

What this tells me is that the dies DO make a point of impact difference, no problem there just a minor scope adjustment. But what’s more important are cycling out cases that even though they look good and have not stretched, there’s still a tensile factor in the brass itself (heating/cooling, reforming, etc) that were at the root of my grouping issue. Someone with more physics knowledge would better explain my layman’s jargon.

Appreciated all the feedback, it helped the gears to get turning.

I would guess the RP cases have a different case volume that is favorable to the load pressure and perhaps the brass is thicker at the necks as well creating good bullet hold. Dies are not magic the are simply dimensional.
Jim

 

[Varminterror]

One thing I have not seen recommended yet is checking your loaded rounds with a minimum chamber spec cartridge gauge. At the very least it will tell you if the brass has been properly sized.

Nah, it really won't. Checking with a minimum spec gauge will only tell you if your brass has been sized to minimum spec, and won't tell you a thing about whether the brass is properly sized for his actual rifle chamber.

I used to be a bit of a Ruger M77 MkII nut, and made a lot of money taking on gunsmithing work which other smiths would turn away on these rifles, and I'm not sure I ever met a MkII with a chamber cut to minimum SAAMI spec.

 

[mdi]

Just my opinion; it takes a really picky gun for die manufacturer channges to make an accuracy difference. I have only reloaded 5 different rifle calibers. But good, very good accuracy is obtained by a load work up. I haven't found a great difference with cartridge peformance by just using diffeent dies. (my 30-06 handloads are made with Lee dies and RCBS died and a Lee collet crimp die. My 308 Win handloads are made with Lee and Hornady dies. Lee dies for 7.62x54r and 303 British and CBS for my .223 Rem). Different dies make very little to no noticable/measurable difference.

 

[AJC1]

Sounds like in your op you may have mixed loads from different sessions giving you a larger group. If your new production is just as good as the old, shoot up the old load then make the scope adjustment and March on. I don't mix brands of brass in the same box, and you observed for yourself exactly why....

 

[lordpaxman]

@Bruce Wambach, welcome to THR!
I don’t have much to add, just following the thread. I didn’t see where you mentioned COL but I’m presuming it’s the same? It also sounds like you don’t have a chrono or at least you could check V. I don’t have the Lee dies but have read they are pretty good at limiting runout - perhaps the RCBS aren’t as aligned?
I would think a change of dies could affect the group spread, but how does that affect the POI? That sounds more like something moved, either due to climate or a mechanical bump.

 

[ms6852]

Maybe the neck tension when sizing is different on each die, causing a different point of impact.

 

[Thomasss]

Just for information sake, What is your case trim size of each group and OAL seating depth?
Many guns do prefer some cases over others and Remington cases are thicker than most.