204 ruger custom reamer

[snipersam]

I have read on here in the past about guys having custom reamers made with a shorter throat, so bullets can be seated close to the lands. I guess I started this post to talk about those reamers. I would like to have one built, and wondering on some numbers. now the factory claims the freebore is to give the bullets a running start so they are able to achieve higher velocities. is this true? 3775 seems to be doable in every barrel I have tried without pressure signs, some I got 3850 with no pressure signs, wit r-10x and h4895. will the shorter throat make finding accurate loads easier on average.

I have a pacnnor super match 1-11 on my vanguard sub moa varmint and it has a chamber made wit a standard 204 ruger reamer. the factory barrel shot good wit 39bk only, at 2.25 col. 40 gr v-max shot terrible. nosler 40 gr shot terrible at 2.25col but shot 1 inch seated out to max mag length, off the top of my head I don't know this measurement. now the pacnor was a piece of work, h4895 and h335 were no good, I tried varget next and it shot 30 gr bergers great seated short. 40 noslers and v-max were a no go either long or short. 45 hornady sp were ok. 39 bk shot good as long as the mag let me seat them, but just ok at 2.25. but id get vertical fliers 1 or 2 in a ten shot group that would open groups to about .8. the other 8 or 9 were in .5 or less. finally I got my hands on some r-10x, 39 bk seated long shoot good now. fliers went away and groups tightned. never tried r-10x wit any of the other bullets and not going to. never spent so much time finding a load for a gun also this barrel seems to need extra powder to get speeds up and a lot of it. what is a max in ur gun for r-10x?

also what barrel life r guys getting I put 3000 rounds on the factory barrel, it was .5-.6 shooter for most of its life, it ended up 1-1.25moa. I got 1100 through this barrel so im already thinking ahead

[wirelessguy2005]

i typically go with zero freebore on all the reamers i have built. Although i will say that the 204 Ruger doesn't seem to mind the jump as much as other cartridges. As far as accuracy goes i believe that the gunsmith doing the work has a bigger impact on overall accuracy than all the other factors of a build combined. Case in point i have used factory barrels rechambered or Green mountain barrels and found great accuracy. Keep in mind that Bob Green does all my gunsmith work and he is a master craftsman in my opinion. Something you didn't mention but i think is very important in a custom reamer is the neck clearance. I always try to end up with a chamber that has .002 clearance over the diameter of the loaded rounds. This keeps brass working to a minimum and can extend the life of your brass by many times over a factory chamber. Typically a factory chamber has .006 overall neck clearance, by minimizing it to .002 clearance with a custom reamer you are effectively cutting the working of the brass in a third. Another factor that is often overlooked is the shoulder angle and case taper. Changing the shoulder angle has a big impact on the overall efficiency of the cartridge. We recently designed a new cartridge called the 20 SCC. The parent case is a 221 fireball, we changed it to a 40 degree shoulder and necked it down to 20 caliber. During testing this cartridge with 19 grains of IMR 4198 and a 32 grain bullet is producing 3,900 fps. When we switched over to Accurate 2200 powder we were able to get 4,100 fps with a 32 grain bullet and 22 grains of powder. These numbers are significantly faster and the cartridge is much more efficient than a 20 VT and i credit much of that to the 40 degree shoulder. I also have a 223 based cartrige necked down to 20 caliber with a 40 degree shoulder that i have been doing some testing with. Overall i am very impressed with the 40 degree shoulder cartridges and they just look so darn cool.

Brad

[snipersam]

ok neck clearance was something I didn't think about, I don't neck turn any of my brass. will .002 overall clearance be a problem? and wat exactly is zero freebore in a 204 chamber?

[Rick in Oregon]

You don't say why you feel you need a custom reamer, other than you think you want to load closer to the lands. In all honesty, if you're not familiar with even the basic fundamentals of chamber/reamer design, then you'd be much better off shooting rifles with SAAMI spec chambers.

Neck clearance is one of the critical primary dimensions of any chamber. Not being familar with even this basic detail could result in a ruined barrel, sky high pressures, personal injury, et al. Consider leade angle, neck clearence, freebore, shoulder datum, chamber length, body taper.......there's many aspects to consider in any reamer design........you get the drift.

One of mine, ground by Dave at PTG:



Here's one of my reamer prints from PTG. As you can see, there's quite a few dimensions to consider, most are critical, this one being no exception, as it's TK's 204 Match reamer that features the .230" "no-turn" neck.....once you go this route, you CANNOT shoot factory ammo in that rifle, so take note and proceed carefully:



Sounds like you need to read-up on the subject prior to spending money and proceeding further. Just a thought......

[wirelessguy2005]

First off Rick makes a very valid point and i agree with him 100%. You need to be familiar with what you are doing when working with custom chambered rifles. I tend to get a little ahead of myself and assume that everybody is an advanced hand loader. My apologies on that.

I don't typically neck turn my brass either. That being said .002 overall clearance is a minimum amount of clearance for a varmint rifle when using good brass such as Nosler or Lapua that has a consistent neck thickness. If you are going to use Rem or Win i would either neck turn or allow a little extra neck clearance.

Zero freebore shortens up the distance between the bullet and where the bullet contacts the rifling. In essence it allows you to accomplish the goal of seating the bullets out to touch or nearly touch the lands. This is good if you are using short bullets like the 32 grain or similar in your 204.

ok neck clearance was something I didn't think about, I don't neck turn any of my brass. will .002 overall clearance be a problem? and wat exactly is zero freebore in a 204 chamber?

[snipersam]

rick I know what ur saying. basically id want the freebore gone. the whole reason I went wit a 1-11 twist was to shoot the other 40 gr bullets. it still only wants the 39 bk. which im totally fine with, I love that bullet, but very hard to find them in stock up here. when they have em I clean out the store. it can take a year to find them again! im thinking that seating the 40 nosler and v-max 20 thou from the lands might be better than jumping God knows wat.

I do use rem and win brass now, but am gonna buy nosler next. but the stuff I have now, and its a lot of it, just lasts and lasts and lasts. so it might take years till I get something better. so for the rem and win brass, what neck clearance is considered good? if one should neckturn for .002 clearance then .006 clearance doesn't sound too bad for no neck turning. am I wrong here?

wirelessguy- I do know wat freebore is but u talk of zero freebore, my question is wat is zero in relation to the 204? what would the ocl be with a 39 bk touching the lands?

[Rick in Oregon]

Before we go any further, can we please dispense with the AOL "ur" crap and communicate like educated adult humans?

[snipersam]

sorry rick I spend too much time on my phone. It becomes a real hard habit to break. It wouldn't happen again.

[Rick in Oregon]

Okay then, the typical factory 204R has roughly in excess of .100" freebore. This was established in order to get the factory claimed velocities in the beginning. And despite common dogma, these rifles shoot far better than one would expect with such excessive freebore.

And like wirelessguy mentioned, a good precision chamber will have right at .002" neck clearance, but remember, this equates to only .001" per side if you will. Most factory chambers run much more, the reason we get split necks from working the brass this much and why most only neck size. When you use the .006" dimension, are you referring to .003" per side, or .006" per side (which would be considered excessive)?

To answer that question about the velocity gain between the standard .223 and the 223AI version, my custom M700 223AI will shoot the 50gr NBT at the same speed my standard 223 will shoot the 40gr NBT......3,680 fps. I gained right at 180 - 200 fps with my improved version, which was worth it to me as I like to dink about with this stuff anyway. Some may not consider the velocity gain worth it when die prices are considered (Redding custom comp dies). But the added velocity in the rat patch shooting 50 grainers compared to the 40's is impressive both in terminal energy (launch factor) and wind sensitivity/deflection.

Here's the comparison between my 204R Sako round alongside my M700 223 Ackley, both loaded to just touch the lands in their respective rifles:



My M700 chambered in 204 Match with a Pac-Nor 11-twist will shoot the 40gr V-Max into one hole. It has the aforementioned .230" "no-turn" neck and .015" freebore. It'll also shoot the 39gr SBK and 40gr NBT almost as good, usually less than .3" and has become one of my favorite "afternoon rat patch rifles" for the wind.

I'm not wireless guy (Brad.....good guy at CRT), but no one can give you the OAL of a 39gr SBK touching the lands.....unless they had your rifle in hand with the Hornady tool in the other......

HTH

[snipersam]

Thanks rick you have answered a lot of questions.

So I'll forget about the neck clearance cause I cant see myself neck turning anytime soon, maybe one day.

I just checked the length of one of my rounds, 2.35, this is as long as I can go and still fit into the magazine. However not all rifles are like this, some are maxed out at 2.26(tikka t3). I would like to stick around this overall length and have the lands in reach. How much freebore should the reamer have to do this? zero? .015 like yours?

In your picture you have the 39 bk seated out a lot more than mine. That is for your sako 204. Then your rem 700 with the custom chamber should have it seated a lot shorter. What velocities can you get wit the rem 700 with this configuration with a good 204 powder like r-10x? For me if I can get 3750-3800 with a 22-23 inch barrel that's perfect

[Rick in Oregon]

Thanks rick you have answered a lot of questions.

What velocities can you get wit the rem 700 with this configuration with a good 204 powder like r-10x?

I'm getting 3,980 fps with RL-10X and the 39gr SBK in my Sako M75V, but at slightly over book max, which is okay in my rifle loaded long.

In my custom M700 204 I can reach the lands no problem with my .015" freebore. Zero would work too, but I wanted the bullet to have a tad room to start out of the case before encountering the lands to keep pressures as low as possible. Everything seems to work as planned; more velocity due to more room in the case with safe pressure limits and being able to reach the lands for maximum accuracy potential.

[Bill K]

Might I add to what Rick mentioned. My 223 AI does just about the same that Rick's does and the gain is not all that much, as he mentions, but I like and enjoy the Ackley case's. If I missed it, sorry for the repeat, but you will also find they slide into the dies easier, need way less trimming and your brass will last longer, unless you go full/full throttle all the time. Bill K