Finding the lands on my Rem 700

[Saxon11]

I did several test to find the lands on my rem 700 sps 308 sa tonight and got mixed results.

I know I am going to get the advice to get an AOL measurment tool, but I don't have one at the moment.

The first thing I did was seated a bullet in a loose case @ 2.994. I put it in my action and closed the bolt. Here are the results when I pulled it out and measured it:
1-2.959 2-2.958 3-2.959

I then did the candle test and found that at 2.953 and 2.948 I got land marks, but at 2.938 there was none.

I filed a groove in a case neck and opened and closed my action, measuring each time:
2.945, 2.937, 2.941, 2.943

From this I believe my lands sit somewhere between 2.940-2.945.

I was wondering if this sounds normal for a 700 short action because it seems a touch long to me?

Also would you draw the same assumption from my data as what I did?

Thanks guys!

 

[Johnboy]

try it again.but this time with a necked sized case and splitting the neck only with a dremal tool.then clean the burrs off and seat a bullet in long.this should help out and allow you to get the bullet out with out a puller.but will have enough neck tention to hold the bullet in place.been doing it this way for years and no problem yet.and you might want to remove the fireing pin this will help out all so.it allows yu to feel the seatting of the bullet in the lands.

 

[K0na_stinky]

What I find happens when I use a case to find the COAL is that the bullet is lightly pressed into the lands and when I extract the round the bullet is stuck in the lands for a second and then gets pulled out after the case has been pulled out a few thousands. Some times less or some times more. So you never get a consistant measurement any time the bullet touches the lands.

So what I do is start off the lands. So when I put the round in the chamber it doesn't change at all. Then I work my way forword towords the lands. If I get any movement at all its touching the lands. I take my time and very carefuly check and recheck until I'm sure the measurement is right.

I'm new to this and I'm sort of having touble getting what I mean across. I hope it helps.

 

[bozo699]

try it again.but this time with a necked sized case and splitting the neck only with a dremal tool.then clean the burrs off and seat a bullet in long.this should help out and allow you to get the bullet out with out a puller.but will have enough neck tention to hold the bullet in place.been doing it this way for years and no problem yet.and you might want to remove the fireing pin this will help out all so.it allows yu to feel the seatting of the bullet in the lands.

What I find happens when I use a case to find the COAL is that the bullet is lightly pressed into the lands and when I extract the round the bullet is stuck in the lands for a second and then gets pulled out after the case has been pulled out a few thousands. Some times less or some times more. So you never get a consistant measurement any time the bullet touches the lands.

So what I do is start off the lands. So when I put the round in the chamber it doesn't change at all. Then I work my way forword towords the lands. If I get any movement at all its touching the lands. I take my time and very carefuly check and recheck until I'm sure the measurement is right.

I'm new to this and I'm sort of having touble getting what I mean across. I hope it helps.

Johnboy,
Pulling the fireing does help in feeling things, and I did it the same way as you for years but KNoa stinky is right more often than not the bullet sticks in the lands,and for that reason it is well worth the $20 investment for a Hornady oal tool and modified case. If a few more $ wont bancrupt you instead of buying the modified case take a fired case from your rifle and take it to your smith or a machinist and have him drill out the primer pocket and use a 5/16 36tpi tap and make your own modified case. If you want to make it just a little easier to use turn just a little off the neck so it fits easier into the throat. It costs very little and you will get a life time use out of the tool.
Wayne.

 

[1000yardstare]

Had a Rem 700 SPS in .308. To have a 155 gr bullet 20 thou off the lands, they weren`t even in the neck of the case.

Have found the same thing in a Rem .30-06 pump, a Rem VSSF .220 Swift and a Rem 700 CDL .35 Whelen.

For some reason Rem cuts very long throats in their centerfire chambers. Might be some kind of lawyer thing. Difficult to build up high pressures with all that freebore.

 

[GermanS1]

Saxon, that length is normal on a Remington 700. I have Western and Remington .308 match ammo made in the 1960 to 1965 time frame that requires that long throat. I don't know which came first here (chicken - egg problem) but Remingtons (including the 40X) have always had a long throat.

I'm looking at the SAAMI standard for the .308 chamber as I type this, but without a loaded rounds and some measuring tools in front of me, I can't determine how close the Remington chamber is to the standard. I'll try to check that later.

 

[RonAKA]

Here is how I do it.

Split Case Method

1. Take a neck sized only fired case, and use a Dremel to cut a single narrow slot in the neck and shoulder.

2. Select a bullet from the box you plan to load and fit it in the split case. Pick a bullet with a consistent flat tip, or file it a touch to square it up. Adjust case by squeezing the neck to increase tension as required. It does not need a lot of tension and just enough hold the bullet.

3. Carefully chamber it, and remove it slowly. If the ejector is pushing the case sideways, use your finger to keep the bullet from dragging on the side of the chamber or receiver.

4. Measure the overall length of the cartridge to the tip of the bullet, and record it.

5. Repeat step 4 until you get consistent numbers within .001". When you think you are close, then just pull the bullet a slight touch out from the self seated position and confirm it consistently returns to that same spot, and record the final length of the cartridge, and record in you loading book. Mark this bullet so you don't mix it up with the rest.

6. This length represents what overall length you need for that specific bullet to touch the lands. In my opinion just touching the lands is a poor position to seat too. I go either 0.010" longer to jam the bullet, or increments of 0.010" shorter to create a jump to the lands. Calculate your desired OAL to give the jam or jump you want, and record that number.

7. Use this marked bullet to load a live round long in the case, and by seating it deeper and deeper by trial and measure match the OAL you have calculated in step 6.

8. At this point methods may differ. Some save this load and use it to set up your die for the next loading session. I have a micrometer style seating die, so I just record the seating position in my loading book and use the test round at the range.

9. This test load, or recorded seating depth in theory is good for that specific batch of bullets, if it were not for throat burning. Especially when new the throat burns so is a moving target. So, especially with a new barrel you may want to repeat this exercise more often, or if you bought a large batch of the same bullets.

 

[Saxon11]

RonAKA: Thats exactly what I did when I used your method, but as in your step 5, I only repeated it 5 times.

Why do you guys think that I can't make it to the lands? using my 175 SMK, I had land marks on my bullet all the way down to 2.950 when I started 2.995. Even at 2.995 the bullet is seated in the case.

 

[RonAKA]

RonAKA: Thats exactly what I did when I used your method, but as in your step 5, I only repeated it 5 times.

Why do you guys think that I can't make it to the lands? using my 175 SMK, I had land marks on my bullet all the way down to 2.950 when I started 2.995. Even at 2.995 the bullet is seated in the case.

Not sure I'm totally following what your concern is... For sure there is going to be huge differences in COAL to touch the lands for different bullet weights and design. The length of the nose varies greatly depending on the slope used. Low drag and high BC bullets have long slender noses, and for the same touch the lands position will measure COAL much larger.

 

[lurcher]

I have tried both the hornady tool and the case neck split with dremel tool. With the split case method the amount of neck tension applied to the brass will cause slight differences in readings

The hornady tool can give you a reading that is slightly short as the modified case is a new case and there will be a headspace difference between it and a piece of fired brass and you are measuring from the base of this case and assuming that this would be the same as measuring from the bolt face. You can buy a 5/16X36tpi tap and make your own modified case to get around this.

The plastic rod on the hornady tool is cheap, I wish it was made out of stainless steel. You can get dimples forming in the slot where the set screw locates, which worriess me as it may affect the accuracy of the tool in time.

another method is the R-P tool. See this post from another forum for pictures. I had a friend make me one it works well. I am pretty paranoid about getting COAL measurements correct and I usually try two or more methods whenever I do it to double-check myself!

 

[bozo699]

I have tried both the hornady tool and the case neck split with dremel tool. With the split case method the amount of neck tension applied to the brass will cause slight differences in readings

The hornady tool can give you a reading that is slightly short as the modified case is a new case and there will be a headspace difference between it and a piece of fired brass and you are measuring from the base of this case and assuming that this would be the same as measuring from the bolt face. You can buy a 5/16X36tpi tap and make your own modified case to get around this.
The plastic rod on the hornady tool is cheap, I wish it was made out of stainless steel. You can get dimples forming in the slot where the set screw locates, which worriess me as it may affect the accuracy of the tool in time.

another method is the R-P tool. See this post from another forum for pictures. I had a friend make me one it works well. I am pretty paranoid about getting COAL measurements correct and I usually try two or more methods whenever I do it to double-check myself!

I agree with you on building your own modified case from a fireformed case, I get better results by far with this method.
Wayne.