20 practical coal

[JB10]

If it has zero freebore, why not seat the bullet a little deeper in the case. As the throat eventually erodes, you could then seat the bullet a little further out.

Thats the plan. I had no worries about it just was not expecting to have dummy rounds made. Thought it was just going to be reamed off of gauges and then i would find the seating depth. This is a rented reamer not cut to my specs on what i wanted for freebore

 

[L.Sherm]

Thats the plan. I had no worries about it just was not expecting to have dummy rounds made. Thought it was just going to be reamed off of gauges and then i would find the seating depth. This is a rented reamer not cut to my specs on what i wanted for freebore

I would just have it reamed and set to the head space guages you don't want to run into a situation were your FL die doesn't work properly.

 

[searcher]

Whatever depth you set your bullets to, keep in mind these small varmint bullets tend to like to be jumped - so I'd not close that bullet in as though it were a target rifle. If you seat them too deep - you can get into the doughnut area - especially with the 39 and 40. Seat too far out, and you have magazine clearance issues in an A/R

For these bullets, this is what my O.A.L.'s are:
32 V-Max 2.250" (1.884" using Hornady tool)
40 V-Max 2.245" (1.880" using Hornady tool)
39 Blitz King 1.880"
These are for my A/R's

 

[JB10]

I stopped by his house tonight to get the reamer back. He seated the bullets to where they were off the lands and dmn, those bullets are into the case. This reamer has 0 freebore. So i gusee i need to get shooting to erode it some!!!

 

[RegionRat]

I stopped by his house tonight to get the reamer back. He seated the bullets to where they were off the lands and dmn, those bullets are into the case. This reamer has 0 freebore. So i gusee i need to get shooting to erode it some!!!

There is a specific tool called a throating reamer that is used to lengthen that jump/seating dimension.
Ask your GS if they have it or will rent/get one and you can then have the seating depth exactly as you want it.

 

[L.Sherm]

He seated the bullets to where they were off the lands and dmn, those bullets are into the case

And how much off the lands?

 

[JB10]

And how much off the lands?

I think he said .010. After i fire a few rounds ill recheck it just to confirm there was not a little burr that got smoothed out. If it shoots ill leave it short. If not ill jave to get it reamed deeper

 

[Coyotefurharvester]

20p was meant to be a ballistic improvement in the AR platform over the 223 and at the same time feed properly(204 R can be an AR mag problem). So with the vmax, just under mag length should be golden. Jump will allow for max performance(fps).

 

[7887mm08]

The 20 practical was intended to be used in 223 mags, therefore keeping 2.25-2.26” oal is most logical.

Exactly

 

[L.Sherm]

I think he said .010. After i fire a few rounds ill recheck it just to confirm there was not a little burr that got smoothed out. If it shoots ill leave it short. If not ill jave to get it reamed deeper

I might have missed it but what bullet and AOL did you end up with it .010 off the lands?

 

[JB10]

Well right now going to test the 32gr vmax. My coal is 2.130. Im really wanting to use the 40gr, so ill start my load work up with the 32's and then make a modified case and remeasure.

 

[JB10]

I just seated some 32s at a longer coal than smith said and no rifling marks on the bullet. Im going to have to check the depth myself once i make a modified case.

 

[L.Sherm]

I just seated some 32s at a longer coal than smith said and no rifling marks on the bullet. Im going to have to check the depth myself once i make a modified case.

I would use the Wheeler stripped bolt method.

 

[Coyotefurharvester]

Vmax bullets should be no problems starting at 2.220 coal if a "normal" 20p chamber , Bergers,Nosler much shorter.

 

[JB10]

Well got to go and try this rifle out today, boy was my seating depth way off. Now that i have piece of brass i threaded it to use my hornady tool to check to the lands. I found a good load today but at a low powder charge of N133. Ill load up some more with a different seating depth and play with some higher charges. I wanted to start low just to make sure worked good in my rifle. I think this will be a shooter.