Recommended COAL for Nosler 80 BT - 243 Winchester

Ok, I've seated the bullets out to far. Question is it shouldn't have happened.
I loaded up some Nosler 80 grn BT's. With my Hornady L-N-L gauge, I get a shaky measurement of around 2.790 to 2.800" COAL, touching the lands. I say shaky because the bullet is so far out its slightly wobbly. I did some math, taking the bullet OAL minus the boat tail length (difficult to get an accurate measurement on this) and seated at a .243 depth. This came out to a COAL of 2.760". I load up twenty of these, with different powders, go to the range, and none of them chamber!!!! What's the deal?
I get back to the house, load up a dummy round, at 2.760", couldn't chamber it, so pushed and got it to chamber. Pulled it out, measured it, and yes, it now measured 2.710" COAL. I loaded up another dummy round with exactly the same results! It would seem, at 2.760", I'm jamming into the lands and the bullet is being pushed into the case. Loaded a third dummy round at 2.700" and it appears to chamber normally.
So, before I go seat all the loaded ones to under 2.710", I thought I'd ask two questions:

1. How can these measurements, with the L-N-L gauge be wrong? I understand I'm not getting the most accurate measurement, but, 2.790" is a long way off from 2.710".

2. Anyone shooting these Nos 80 grn BT's, in a Savage .243; what kind of COAL's are you seating to?

Thanks

What does the book tell you about it...They must have a OAL requirment....

Quote:

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Originally Posted by acemisser

What does the book tell you about it...They must have a OAL requirment....

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The only OAL listed, in the Nosler data, is the recommended cartridge max OAL of 2.710". That's for any bullet, irrespective of brand, and I believe, is based on magazine feeding. They do not list a recommended COAL for that bullet in the 243.

beartooth, It appears to me the "problem" might be a very slight error in one of the steps in your measuring technique. Are you using a 3/16" wood dowl rod inserted from the muzzle to gently push the bullet back-and-forth using the dowl rod and the plastic push rod in the LNL gauge until you are satisfied the bullet's ogive is just touching the lands?
Perform this procedure three or four times and record each of the measurements. Then use the smallest measurement or average of the three or four measurements.

Are you using a properly sized Comparator Bushing (.24 cal.) to make these measurements?
Is the comparator body properly affixed to your caliper?
When you measure from the base of the cartridge to the ogive of the seated bullet does that measurement include the length of the comparator seated on the caliper?
If using the caliper with the comparator attached do you reset the caliper to "0.000" which takes the length of the comparator out of the base-to-ogive measurement?
Is your caliper consistently accurate?
You mention OAL and COAL I am not certain all participant in this thread have the same definition for OAL and COAL. The Cartridge Overall Length of my .243 rounds, when measured from the base of the cartridge to the tip of the Horn. 87 gr. spire point bullet is 2.710". At this length the bullet "jumps" .020" to the lands. However, this measurement is meaningless to me except that the cartridge fits into the rifle's magazine. I keep this "dummy round" as the standard for THAT BULLET in MY RIFLE. Seating dies are adjusted to allow a longer or shorter "jump" for each of the bullets I shoot.

If you do not yet have a bullet Comparator, purhcase one. Hornady and Sinclair models are both very good.

My apologies in advance if you are already doing much of what I suggested. I would rather provide a little more info than you need rather than not quite enough.

Best Wishes.

I thought about this last night. My best guess is that the bullet drooped when I inserted it, and the modified Hornady case, into rifle. This gave me an erroneously long measurement. I would've thought I'd catch this because I repeat the process a minimum of three or four times. In any case, based on the dummy rounds being jammed in and the lands pushing the bullet back to a 2.710" COAL; I reseated all of these to a COAL of 2.680", guesstimating this to be .020 - .030 back. This was initial load development with this bullet. I took them out to the range, this morning, and shot some outstanding groups. H380, Varget, and IMR4350 all produced one, ragged hole groups from .284 to .533 inches! The only powder it didn't care for was Reloder 15.
I don't like to do business this way and I still need to have a plan/procedure/info for where to seat these shorter bullets since I have some Nosler 55 and 70 grainers.

John_M,

I've never heard of a wooden dowl on the front side of the bullet. I'm interested and curious. Where would one procure a 22-24 inch 3/16" wooden dowl?
Also, I do not have comparator bushings. I know a set can be bought for my Hornady L-N-L gauge. I've just never understood the purpose of the comparator bushings. In my case I insert the bullet, with the modified case, 'till the bullet touches the lands. I then measure the cartridge OAL. I repeat the procedure a few times to ensure I'm getting consistent measurements. I seat the loaded cartridges to the same cartridge OAL I measured with the modified case, bullet, and L-N-L gauge. So, I don't know what a comparator bushing would do to help. Also, I do check the caliper at zero prior to taking the measurements.

beartooth, A 3/16" wood dowel should be available from your local hardware store or lumber yard. They come in 3' and 4' lengths. I use the 4' length. The instructions accompanying your Hornady LNL OAL gauge describe how to use this dowel rod. You mention that you do not have "...the bushings..." for the LNL OAL gauge. The bushings are for the LNL Comparator - NOT the LNL OAL Gauge.

Here is the Hornady LNL Comparator I use:http://www.midwayusa.com/product/231...with-6-inserts

You need BOTH the Hornady LNL OAL gauge AND the Hornady LNL Comparator to properly measure the length of the cartridge from the base of the brass to the ogive of the seated bullet. The procedure you use to measure Cartridge Overall Length DOES give you the length of the cartridge from the base of the brass to the tip of the seated bullet. However, this measurement is useful only to determine if the cartridge will fit into the rifle's magazine. This measurement has nothing to do in determining the length of the cartridge from the base of the brass to the ogive of the bullet. You need a Comparator with the proper bushing for this base-of-brass to ogive measurement. The Comparator set in the link above includes the .24 cal. bushing you need fdor the .243. The set also includes bushings you will need for the 7mm-08 Rem. and .223 Rem. Hang in there. When I first started using these two gauges I suffered the same confusion it seems you are experiencing.

I had a long and detailed explanation of how to use these two gauges but hit an improper key on my keyboard and erased everything. Hornady provides excellent explanations with drawings of how these two gauges are used. Their directions are much clearer than anything I had prepared.

Feel free to ask if anything I have said needs clarification.

Good luck and best wishes.

Edit: You will want to assemble an unprimed dummy round for the different bullets you are using. So, you should make a dummy round for the 80 gr. Nosler BT. If you use a heavier or lighter Nosler bullet you should also make a dummy round for each of these bullets. The position of the ogive on each of these different bullets will vary a few thousandths of an inch. If measured really carefully, you will also notice that the position of the ogive varies a teensy bit on many of the bullets out of the same box. Some manufacturers are more precise than others in their manufacturing tolerances.

Edit: I agree with the excellent description provided below by thomae.

Quote:

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Originally Posted by beartooth91

I've just never understood the purpose of the comparator bushings.

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The comparator allows you to "compare" the length from the base of the cartridge to a spot on the ogive (curve of the bullet) that is the same diameter on two bullets.
By measuring the difference between a bullet pushed to the lands in your chamber, and another bullet loaded to a slightly different length, you can find out how far from (or into) the lands you are loading that second bullet.
The reason it is not recommended to measure from base to tip or "meplat" (as it is technically named), is because many times there is some distortion of the tip (especially with lead tipped bullets) that will result in false or inaccurate readings. One bullet's meplat may be squished down more than another. By using the appropriate comparator insert to measure to a known diameter along the ogive, one ends up with a more precise set of measurements.

I hope that makes sense to you. If not, please ask questions.

Well, I guess I'll have to get a comparator.

So, how does one figure out the seating depth(s) for a shorter bullet that's too short to touch the lands and get an accurate measurement? In my case, I have some Nos 55 and 70 grn BT's. I haven't been able to find any published tested/recommended COALs for these bullets.

bearooth91, All of your rifles are Savage so I would assume they all have standard SAAMI spec'd chambers. As a general bullet seating specification I like to have the bullet seated to near the bottom of the neck of the brass. If that is not possible, I like to have it seated at least to the depth of one diameter of the bullet. So, my .243 rounds all have the bullets seated approximately to the bottom of the neck or to a minimum depth of .243" (approx. 1/4") into the neck. This minimum seating depth keeps the bullet concentric with the barrel and prevents it from falling out of the case during normal use. This seating specification meets my needs for the 87 gr Hornady and 90 gr Nosler bullets. Perhaps, if you are not loading a magaine but using your rifles as a single shot you can "cheat" a little on the seating depth because the loaded round will probably not be subjected to rough use. The shallower the bullet is seated, the greater the chance that it will not be concentric with the chamber and/or will fall out of the case while being chambered.

Here's what I would recommend for the shorter bullets which ogives cannot reach the lands: Load them as closely to the lands as possible while still maintining the minimum requirement for seating depth. The last thing you need or want is to have the bullet seated so lightly that it is not concentric with the barrel (horrible accuracy) or falls from the case (at least very messy and perhaps very dangerous) while feeding into the chamber.

If you do purchase the Hornady LNL Comparator and have additional questions about its use, ask away. Someone is usually available to help.

I have read that Sinclair also makes a very good Comparator. It is priced about the same as the Hornady Comparator and works about the same way. I have not seen the Sinclair unit so cannot comment on its attributes.

Good luck and best wishes.

beartooth91, Because of a couple of comments you made I am not certain you have a true Hornady LNL OAL Gauge. Is it one of these?: http://www.midwayusa.com/product/570...ge-bolt-action

I assume you are using a .243 Win. case, modified by Hornady for use with their LNL OAL gauge. If so, adding the Comparator and a Hornady modified case for both the 7mm-08 Rem. and .223 Rem. are all you need for accurate seating of all bullets for these three cartridges.

Good luck.

beartooth91, Because of a couple of comments you made I want to be sure we are both talking about the same Hornady LNL OAL gauge. Is your gauge one of these?: http://www.midwayusa.com/product/570...ge-bolt-action

Are you using a Hornady modified case for the .243 Win? One of these?:http://www.midwayusa.com/product/128...243-winchester

If so, all you need is the Comparator and a Hornady modified case for your 7mm-08 Rem. and .223 Rem. You will then have the tools necessary to precisely measure the length of "jump" for all bullets in these three cartridges.

Yes, both of the above are what I have. I also have the modified cases for the 7mm-08 and 223.
I've thought and thought about this. I also went through the Hornady instructions. In my case - and what I neglected to mention above - is that I repeat the the measuring exercise, with the L-N-L gauge, modified case, and bullet at least 3-4 times and with different bullets from the same pack. All the measurements come out right on with one another or within +/- .002-.003". That's probably why I've never invested in a comparator. The one exception is a bunch of Barnes 7mm 154 gr TSX bullets I was given. These are the original TSx's and not the tipped ones. I get measurements all over the place +/- .010 to .015 with these (the main reason why I've never loaded any up). I'm guessing the comparator would help me with those.

beartooth91, You are on the right track and almost to the finish line for precision bullet seating. The Comparator will definitely help with the Barnes bullets. Using the Comparator will allow you to accurately seat the bullets so you have exactly the "jump" you want. All of the rounds will have the same "jump" (just what you wanted) but the Overall Length of each Cartridge from base of brass to tip of bullet will be slightly different(Who cares?). Even though each of the rounds will be a different length, most, if not all of them, will probably still fit in the rifle's magazine.

A folded sheet of instructions come with the Hornady LNL OAL Gauge. The inner, middle part of those instructions explains how to use the 3/16" dowel rod in the bullet fitting process.

I noticed your 100 yd. targets on another topic. Great shooting! Those bullets were seated with ~.030" "jump". Now you can experiment a little. Load some rounds with .025", .020", .015", .010", and .005" "jumps". Once you find the sweet spot, load up a few more rounds with a "jump" .002" shorter and longer than your favorite.

Once you find the best "jump" distance (they might all like the same) for each of the bullets you use, you can fiddle around with different loads of different powders. This is where you start going nuts trying to achieve true perfection in accuracy. This is very time consuming and very enjoyable.

Once you start using the LNL OAL Gauge and the Comparator you will wonder how you ever got along without them.

Good Luck.

I need to bump this thread, because there's something else going on which is giving me erroneous measurments.
Last week, I bought the companion Hornady Comparator with the 6 inserts. I was kind of forced to because finding the lands, in my .223, with 5 different Hdy 52 grn AMax bullets, gave me 5 different OAL's within a span of .010". One of the measurements was almost .015" off the shortest one! Once I put the comparator on, everything was the same, within .001". Ok, so, I understand the need for the comparator when one has a batch of bullets with different lengths.
Back to my .243 and my first post.
The exact same thing happened to me, with the comparator, as did before, in my first post. I continue to measure the Nosler 80 BT's around .030" long - with or without the comparator.
Did five last night, came up with a comparator OAL of 3.285". Loaded up a dummy round, it chambered with resistance, remeasured it and rifling contact had pushed it to 3.255".
I keep thinking about this. It does seem the modified case, when inserted into the chamber, is a bit too tight. Could it be I'm not getting the case in all the way which is giving me a longer than normal measurement? Maybe my 243 has a tight neck chamber?
Thoughts?

Thanks

I have a load with the 80 grain ballistic tips for my E.R. Shaw barrel that shoots in the .3's pretty consistantly.
I cannot decide if 2.670 or 2.720 produces the best results for me as they are both in the .3's ballpark. The 2.720 is still .070 off the lands in my barrel. I am using h4350 at 40.2 grains.

beartooth91, Have you tried chambering a factory round? I would assume that if a factory round chambers properly, the rifle's chamber is not causing the problem. The "problem" would seem to originate in one of the steps in your reloading process.

I would also assume that if a factory round does not chamber properly, the problem might indeed be in your rifle's chamber.

Good luck.

beartooth, maybe these videos wil help some.
http://www.youtube.com/watch?v=WCPgKNp8i7o
http://www.youtube.com/watch?v=Zlv1N0qIAwI