Bushing / Neck Tension issue.

[64Rambler]

I started playing with neck tension recently for my 6BRA. I started with a Wilson 266 bushing and it gives me ~0.003" interference from loaded, and the sized neck comes in at 0.2660-0.2665" with calipers, loaded round is 0.2690-0.2695" (yes, I know I should be using a micrometer and Christmas is coming, so that will solve that issue...). Then I ordered a Wilson 267 and found a good deal on a Redding TiN 265. The 267 gives me 0.2670-0.2675", but the TiN 265 is giving me 0.2630-2635". I had heard that the Redding TiN bushing sized a bit large, but I found the exact opposite. I ran gauge pins in all of them and they're right where they should be, within 0.0002". So I ordered a Wilson 265 bushing and got the exact same result; 0.2630-0.2635". And it feels like that much more interference when seating a bullet. This seems like the opposite of spring back. This is with both Alpha and Lapua brass, flame annealed. What am I seeing/missing here?

 

[NF1E]

Sounds like time for a Sinclair or other neck expanding mandrel to help out with desired neck tension my friend. Works wonders, in my opinion.
Whatta Hobby!

 

[SVT_Tactical]

I agree, a mandrel right before seating is what I use to control neck tension.

 

[JFrank]

I started playing with neck tension recently for my 6BRA. I started with a Wilson 266 bushing and it gives me ~0.003" interference from loaded, and the sized neck comes in at 0.2660-0.2665" with calipers, loaded round is 0.2690-0.2695" (yes, I know I should be using a micrometer and Christmas is coming, so that will solve that issue...). Then I ordered a Wilson 267 and found a good deal on a Redding TiN 265. The 267 gives me 0.2670-0.2675", but the TiN 265 is giving me 0.2630-2635". I had heard that the Redding TiN bushing sized a bit large, but I found the exact opposite. I ran gauge pins in all of them and they're right where they should be, within 0.0002". So I ordered a Wilson 265 bushing and got the exact same result; 0.2630-0.2635". And it feels like that much more interference when seating a bullet. This seems like the opposite of spring back. This is with both Alpha and Lapua brass, flame annealed. What am I seeing/missing here?

Wilson bushing are tapered, I like them that way because I can flip them over for a tiny extra squeeze, but regardless. I don’t get axle wrapped over trying to measure the bushing ID or mess with mandrels, just size a case and compare the neck OD to a loaded round at the CASE MOUTH and go shoot a bushing ladder at distance.
For a .269 loaded round, I would test a .266-.265-.264.

One will stand out’ then test a smaller one.

 

[243winxb]

bushings

• Unlike some other brands (like Redding, which are generally straight), Wilson bushings are designed with a slight internal taper (around 3 degrees).

Redding recommends against sizing down more than approximately 0.008" in a single step. Attempting to size down more in one pass can lead to problems such as excessive case neck runout (poor concentricity) and can cause the actual sized diameter to be smaller than the bushing's marked size due to increased brass springback and stress.

 

[64Rambler]

sizing down more than approximately 0.008" in a single step

That certainly isn't the intent, but seems to be the outcome. I'm running a 272 chamber and fired brass matches that well. The 265 bushings (straight or tapered) are giving me 2 thou more than design, pushing actual step down to 0.0085"
So I'll try 267, reanneal, then 265 and see what I get.

 

[64Rambler]

Sounds like time for a Sinclair or other neck expanding mandrel to help out with desired neck tension my friend. Works wonders, in my opinion.
Whatta Hobby!

View attachment 1713297

I have 21st Century mandrels and usually use them for virgin brass to correct any dings in the necks, but will give it a go for this.

 

[NF1E]

I think that if all necks have the same ID, you might just be a happy camper. Not so dependent on neck wall thickness. Whatta Hobby!

 

[ShtrRdy]

• Unlike some other brands (like Redding, which are generally straight), Wilson bushings are designed with a slight internal taper (around 3 degrees).

Redding recommends against sizing down more than approximately 0.008" in a single step. Attempting to size down more in one pass can lead to problems such as excessive case neck runout (poor concentricity) and can cause the actual sized diameter to be smaller than the bushing's marked size due to increased brass springback and stress.

I thought the threshold was sizing down by more than 0.004" in one step.

 

[Killick]

My method with fired brass:
1)Clean
2)Burn-(anneal)
3)FL Size-.002” under desired inside neck dim. (Imperial Sizing Die Wax)
4)Trim/Chamfer/Deburr...if needed
5)Graphite inside neck (Imperial Dry Neck Lube & Media)
6)Wipe off outside of case body/neck
7)Mandrel to desired neck dim.

 

[Dave Way]

Are you properly annealing your cases? With flame annealing it can be tricky to heat consistently to the proper temperature. Use temperature paint or an IR temperature gun. My guess is the cases aren’t reaching a high enough temperature to relieve stress. You will see more consistent neck sizing, shoulder bump and neck tension if you anneal properly

You don’t say if you’re neck turning. That will also play a role in consistent neck tension.

Dave.

 

[rjtfroggy]

I had to order 2 new bushings yesterday (smaller sizes) to accommodate my 30x47. I ordered SAC standard bushings, $40 apiece plus shipping, almost $100 for 2. Can't tell me there is no inflation, bushings used to be 14-17 $ apiece. Maybe not the SAC's, but in order to get the sizes I wanted they were the only ones with them in stock.
I guess I might have to buy an annealer.

 

[L.Sherm]

With Lapua brass i would try not annealing at all, its worked out way better for me instead of flame annealing.

 

[64Rambler]

Are you properly annealing your cases? With flame annealing it can be tricky to heat consistently to the proper temperature. Use temperature paint or an IR temperature gun. My guess is the cases aren’t reaching a high enough temperature to relieve stress. You will see more consistent neck sizing, shoulder bump and neck tension if you anneal properly

You don’t say if you’re neck turning. That will also play a role in consistent neck tension.

Dave.

No turn on necks yet, though I do have a set of 10 pieces that I cleaned up a bit, removing just enough to touch 80-90% of the diameter, but they don't shoot any better than the unturned brass. I have 0.003" clearance on a loaded round, versus the print neck diameter.
I heat 1 sec past 700F Tempilaq melt. There seems to be a lot of discrepancy for the proper annealing temp. I've seen everything from 650F to 1100F and from "you have to get to a dull red glow to be properly annealed" to "a dull red glow will ruin your brass". I've been adding a bit more time in the flame to see what the effect is on target.

 

[L.Sherm]

I've been adding a bit more time in the flame to see what the effect is on target.

Test some new Lapua brass that hasn't been annealed you may be surprised.

 

[foxguy]

With Lapua brass i would try not annealing at all, its worked out way better for me instead of flame annealing.

??? Caliber

How many firings are you getting on your brass.

 

[6BRA]

I think that if all necks have the same ID, you might just be a happy camper. Not so dependent on neck wall thickness. Whatta Hobby!

If you have 2 cases with the exact same ID, and the neck walls are different, say, .010 to .013.
Which case will yield more neck tension / grip on the bullet? Neck tension will be influenced by thickness of the brass. Perhaps even trim length as a longer surface area of bullet grip will apply more pressure.
On this same note...a full length non bushing die will typically add another .100 of surface grip to the bearing surface over a bushing die. Seems to be a lot more than just inside diameter to me.

 

[JFrank]

With Lapua brass i would try not annealing at all, its worked out way better for me instead of flame annealing.

I’m with you, it takes me a few cycles to get my brass all evened out and shooting consistently so the last thing I’m going to do is take a blow torch to a perfectly good case and ruin my bullet hold.

 

[Dave Way]

I’m with you, it takes me a few cycles to get my brass all evened out and shooting consistently so the last thing I’m going to do is take a blow torch to a perfectly good case and ruin my bullet hold.

Or you anneal every time and have the same uniformity from the very first firing.

Dave.

 

[NF1E]

So nice to have choices. I am one of those goofballs that anneals after every firing and yes Lapua brass gets the treatment. Until I started that process, I was never able to keep my SD down to mid single digits. If it works for you, enjoy. That's what it's all about. Whatta Hobby!