Too much freebore? Need help.

[TeaRex]

I recently had a 6.5x55 built and did not specify the a freebore / throat length I wanted, but I let the builder know that I was planning on shooting Berger 140 Hybrids / VLDs.... very long bullets.

Despite that 6.5 bullets are IMPOSSIBLE to find right now, I think that I have an issue with the amount of freebore.

When I seat a bullet so that it just touches the lands, I end up with only 0.240" of bullet grip. So to get "one caliber" of bullet grip, I would need to jump 0.024", which VLD bullets tend not to like (and I can confirm - no good groups so far with jumped VLDs).

Would y'all consider this an issue? Either way, I'm not really sure of a solution, other than going with <0.264" grip to get the VLDs jammed. If there was a "longer" bullet, that might work, but I don't think there are any available with comparable performance.

PS - If y'all have any 140 VLD/ 140 Hybrid / 142 SMK that you would be willing to sell/trade or if see any in the store, please let me know. I'm down to <50 bullets... getting desperate.

 

[DroidSniper]

Excuse this question as I have never owned a 6.5 is there a heavier bullet that would be longer and thus take up some of that freebore?

 

[TeaRex]

Excuse this question as I have never owned a 6.5 is there a heavier bullet that would be longer and thus take up some of that freebore?

Unfortunately, no. Any bullet that I can find >142 gr is essentially a round nose bullet with poor BC, similar to waht was used in the original 6.5x55 Swedish Mausers.

 

[bjay]

You said you told builder youl be using hybrids but your using VLD to measure FB? Hybrids and VLD is two diff bullets.
Vld and AMAX are pretty close on working on same freebore but not vld and hybrids.i think you can only go one way..BUT a lot of rifle takes both pretty wel

 

[TeaRex]

You said you told builder youl be using hybrids but your using VLD to measure FB? Hybrids and VLD is two diff bullets.
Vld and AMAX are pretty close on working on same freebore but not vld and hybrids.i think you can only go one way..BUT a lot of rifle takes both pretty wel

The VLD is 0.032" longer from base to ogive than the Hybrid from my measurement. Either way, the freebore is still too long to touch the lands without having less than 1 full diameter of bullet grip.

 

[SPAK]

Have you played with your charge weight at all?

 

[TeaRex]

Have you played with your charge weight at all?

Yes, I've tried a wide range of charges with RL-22, IMR 4831 and IMR 4350. IMR 4350 seems to be the best so far, but still not very satisfying groups.

 

[SPAK]

I don't think seating into the lands is a hard and fast rule with VLDs. You're rifle very well may prefer vld bullets to be "jammed"
or into the lands but You should be able to find a good optimal charge weight and then play with seating depth with the vld's to find accuracy. Berger Tips for Loading VLD Bullets « Daily Bulletin

If you can find it, I'd try some h4350 or h4831sc.

 

[jim_k]

Seat the Berger VLD so that the freebore is 0.25". That's right--1/4"! Give it a try. Two long freebore 6.5 barrels I had shot about 0.3" for 5 shots at 100 yds., then I got one with a short throat, and I can't get it to shoot for crud.

 

[TeaRex]

Have you played with your charge weight at all?

Yes, I've tried a wide range of charges with RL-22, IMR 4831 and IMR 4350. IMR 4350 seems to be the best so far, but still not very satisfying groups.

 

[TeaRex]

Thanks for all the responses... keep 'em coming.

I appreciate the comments so far, but I'm still curious if it is acceptable to have ~0.220" grip on a 0.264" bullet?

I understand that I can start working the other direction and jump bullets a looong way. I am just curious for now if <1 diameter bullet grip will work if there aren't other solutions.

 

[Assault116]

I've got a box of 100 of the VLD Long Range 140's that won't work in my rifle (too long for mag when loaded where they need to be) that I'd be happy to part with.

But you might want to confirm dimensions before you buy as they may not be what you want/need.

They measure as follows.

L= 1.416
Base - Ogive =.720
Bearing Surface = .529
L of BT = .191
L from Ogive to Tip = .696

 

[Assault116]

Thanks for all the responses... keep 'em coming.

I appreciate the comments so far, but I'm still curious if it is acceptable to have ~0.220" grip on a 0.264" bullet?

I understand that I can start working the other direction and jump bullets a looong way. I am just curious for now if <1 diameter bullet grip will work if there aren't other solutions.

it should work as long as you can retain some concentricity. I'd also check on a chronograph to see if speeds are consistent and watch your brass for signs of gasses coming back into the chamber.

 

[Edds]

The VLD is 0.032" longer from base to ogive than the Hybrid from my measurement. Either way, the freebore is still too long to touch the lands without having less than 1 full diameter of bullet grip.

The Berger spec sheet shows .090" difference.

 

[oldfatguy]

You are aware that the free bore will grow as the round count goes up, aren't you? My Remmy, FB grows about 0.001" in 70 rounds. So, if you eventually find some bullets you are going to be jumping sooner or later.

OFG

 

[TeaRex]

The Berger spec sheet shows .090" difference.

I just measured again, I still get 0.034" difference to ogive.

 

[TeaRex]

You are aware that the free bore will grow as the round count goes up, aren't you? My Remmy, FB grows about 0.001" in 70 rounds. So, if you eventually find some bullets you are going to be jumping sooner or later.

OFG

Yes... I have actually already noticed more than I expected. From the ~220 rounds I've fired so far, I've gotten almost 0.010 throat erosion from this bartlein barrel! None of the rounds have been significantly hot, but all the bullets have been ones with long bearing surfaces.

I'm hoping that the erosion slows down and levels off some...

 

[TeaRex]

I've got a box of 100 of the VLD Long Range 140's that won't work in my rifle (too long for mag when loaded where they need to be) that I'd be happy to part with.

But you might want to confirm dimensions before you buy as they may not be what you want/need.

They measure as follows.

L= 1.416
Base - Ogive =.720
Bearing Surface = .529
L of BT = .191
L from Ogive to Tip = .696

Looks like they're a touch shorter than what I've got, but they'll help fill the gap until bullets are back on the shelf. I appreciate the offer... I will PM.

 

[ranger1183]

Sounds like the 6.5mm 155 grain Sierra Matchkings are exactly what you are looking for. They are part number 9570 and are very hard to find. I still have a few thousand of them left. Here is a PDF reference for you.

http://www.sierrabullets.com/documents/BallisticCoefficient-rifle.pdf

BTW, as of right now I found heavy 6.5mm target bullets at MidwayUSA, Bruno's, Graf & Sons and Powder Valley. Lots of Lapua out there. Some Hornady, Sierra and others.

 

[Diablo]

Thanks for all the responses... keep 'em coming.

I appreciate the comments so far, but I'm still curious if it is acceptable to have ~0.220" grip on a 0.264" bullet?

I understand that I can start working the other direction and jump bullets a looong way. I am just curious for now if <1 diameter bullet grip will work if there aren't other solutions.

Maybe, according to the Berger Reloading Manual (page 137) "There is no absolute minimum amount of bullet that must be seated. You just want enough of the bullet seated so that it can't be dislodged accidentally during storage and transport."

If you will go to the Berger website, you should be able to find Erick Stecker's guidance about how to determine the optimum seating for their VLD bullets. It is titled "Getting the Best Precision and Accuracy from VLD Bullets in Your Rifle".

According to Eric, the VLD will probably have a "sweet spot" that is about .030" to .040" wide, somewhere in the region between touching the lands to a jump of 0.150" off the lands.

His article provides a methodology for testing to determine the "sweet spot" for the VLD with your rifle.

If you can access the Berger Handloading Manual, the same information is on pages 100 and 101 for the VLDs.

One other hint, anyone that has worked with the excessive Weatherby freebore has probably learned that concentricity of the loaded round is important for accuracy, especially when it is impossible to set the bullet out near the lands.

If this doesn't help, have the barrel "set back" and the chamber corrected.

 

[Edds]

I just measured again, I still get 0.034" difference to ogive.View attachment 17492View attachment 17493View attachment 17494

What is the ID of the tool you are using? I think that is a tool designed to compare the length of same style bullets. You aren't measuring base to Ogive. You are measuring base to a point on the nose. According to Berger, the VLD measurement should be .700" and the Hybrid should be .610".

 

[TeaRex]

What is the ID of the tool you are using? I think that is a tool designed to compare the length of same style bullets. You aren't measuring base to Ogive. You are measuring base to a point on the nose. According to Berger, the VLD measurement should be .700" and the Hybrid should be .610".

That is the Hornady bullet comparator, and you are correct, it is only measuring to a specific diameter on the nose. Maybe 0.250" or something like it.

That being said, do you think the difference in ogive angles is big enough to explain the difference between the book 0.090" and 0.034"? Part of the difference could also be the length of the boat tail. Just by eyeing it, the angles look a bit different, so measuring from the base would add additional error when stating bearing surface length...

 

[Edds]

The Hybrid has a longer BT, .212" vs .200". The VLD has a longer bearing surface, .500" vs .398". The angle will make a difference. A vld will typically make contact at the end of the bearing surface. The Hybrid will contact before the end of bearing surface.

 

[sandwarrior]

TeaRex,

Typically, when you ask for some freebore, or 'throated for a certain bullet', you give a dummy round loaded to the shortest you would load to your gunsmith, so that he can throat/freebore your barrel to your liking. If you didn't do this, it's kind of on you. But, he should have known about that. So, it's kind of on both of you. Being a good gunsmith/businessman he should normally want to make the customer happy.

I would take the rifle back and at least ask him to split the difference and freebore/throat the rifle to what you want.

 

[Frank Green]

Jamming the bullets into the rifling or having them just touch the rifling doesn't guarantee better accuracy. I've seen guns with up to .060" off the lands shoot better then having the bullets touch. This applies to VLD bullets as well. A buddy of mines palma rifle he was jamming his bullets .020 in to the rifling. We had this very conversation. He went to the range with all of his ammo loaded long and he took a hand micrometer seater die with him. He took 10 - 20 rounds at a time and seated the bullets .005" deep on each test lot. His starting load with .020 jam off the bench shot .7 moa at a 1k yards. He seated the bullets up to like .040" off the lands during testing. His best groups he got was .020" off the lands and the groups shrunk to 1/3 moa. So that's where he ended up running the loads in that rifle/barrel.

I have some factory Swiss Ruag .338 Lapua ammo with 300gr. and 250gr. factory loads. The 300gr. bullets are jumping a full .100 and will shoot 1/2moa or better (and yes I have a shorter throat than a stock .338 Lapua spec. to begin with) and the 250gr. bullets are jumping even more than that but still shot really decent for box ammo as well. Averaged around .75 moa. The 250's are jumping .160" with the factory ammo.

I would load some ammo up and start them .010-.020 off the lands and see how it shoots.

The thing of having at least caliber diameter of the bullet seated into the case is a old standard. As long as your bullets are being seated into the case straight (not a lot of run out) I don't go with that rule all the time.

A standard 6.5x55 chamber spec. has a long throat because the factory ball ammo was loaded with a 156gr. bullet. You should give a sample round to your gunsmith if you want the bullets seated to a certain depth or send a sample round and have a reamer made to match your sample round.

Our 6.5x55 match reamer with 140gr. bullets (Sierra's) and I have the bullets set up so the base of the bullet is in the shoulder junction of the case. Not only did I shorten up the throat but also the throat diameter. The standard spec. on a 6.5x55 throat diameter is .269 or so if I remember correctly. I changed it to .2645".

Load some up and shoot it and see what it does.

Later, Frank
Bartlein Barrels

 

[diego-ted]

My 6.5 x 47 would shoot the same 1/2 moa group with Berger 130 VLDs using either a 5k jam or a 120k jump!

Ted